CONTRIBUTING - an update with some addtions and clarifications

Pass 3, add back SPDX and examples. Change copyright reqs.

Signed-off-by: Ted Hess <thess@kitschensync.net>

CONTRIBUTING.md

@@ -1,25 +1,82 @@
-# Contributing Guidelines
+# Contributing Guidelines  
+(See <http://wiki.openwrt.org/doc/devel/packages> for overall format and contstruction)
+
+All packages you commit or submit by pull-request should follow these simple guidelines:
 
-Please make sure that all packages you commit or request to pull:
 * Package a version which is still maintained by the upstream author.
-* Have yourself or another person listed in the (PKG_)MAINTAINER field.
 * Will be updated regularly to maintained and supported versions.
-* Have no dependencies outside the openwrt core packages or this feed.
-* Are tested to run (or at the very least tested to compile sucessfully)
+* Have no dependencies outside the OpenWrt core packages or this repository feed.
+* Have been tested to compile with the correct includes and dependencies. Also, test with "Compile with full language support" found under "General Build Settings" set.
+* Best of all -- it works as expected!
+
+Makefile contents should contain:
+
+* An up-to-date copyright notice. Use OpenWrt if no other present or supply your own.
+* A (PKG_)MAINTAINER definition listing either yourself or another person in the field.  
+    (E.g.: PKG_MAINTAINER:= Joe D. Hacker `<jdh@jdhs-email-provider.org`>)
+* A PKG_LICENSE and optional PKG_LICENSE_FILE definition showing the license type and what file(s) in the package, if present, contain it respectively. The license type tag should be in the form suggested by the Software Package Data Exchange (SPDX) license list. Using these normalized tags will aide us in filtering packages based on license type. See below for a abbreviated list of some common license tags.
+    (E.g.: PKG_LICENSE:=GPL-2.0+; PKG_LICENSE_FILE:=COPYING)
+
+Commits and pull-requests:
 
-Please make sure that all commits you make to this repository:
-* Are signed-off (see https://dev.openwrt.org/wiki/SubmittingPatches#a10.Signyourwork)
-* Have a proper description prefixed with the package name
+* Have a useful description prefixed with the package name  
+    (E.g.: "foopkg: Add libzot dependency")
+* Include Signed-off-by in the comment  
+    (See <https://dev.openwrt.org/wiki/SubmittingPatches#a10.Signyourwork>)
 
 If you have commit access:
+
 * Do NOT use git push --force.
 * Do NOT commit to other maintainer's packages without their consent.
 * Use Pull Requests if you are unsure and to suggest changes to other maintainers.
 
 Release Branches:
+
 * Branches named "for-XX.YY" (e.g. for-14.07) are release branches.
 * These branches are built with the respective OpenWrt release and are created
   during the release stabilisation phase.
 * Please ONLY cherry-pick or commit security and bug-fixes to these branches.
 * Do NOT add new packages and do NOT do major upgrades of packages here.
 * If you are unsure if your change is suitable, please use a pull request.
+
+####Common LICENSE tags (short list)  
+(Complete list can be found at: <http://spdx.org/licenses>)
+####  
+
+| Full Name | Identifier  |
+|---|:---|
+|Apache License 1.0|Apache-1.0|
+|Apache License 1.1|Apache-1.1|
+|Apache License 2.0|Apache-2.0|
+|Artistic License 1.0|Artistic-1.0|
+|Artistic License 1.0 (Perl)|Artistic-1.0-Perl|
+|Artistic License 1.0 w/clause 8|Artistic-1.0-cl8|
+|Artistic License 2.0|Artistic-2.0|
+|BSD 2-clause "Simplified" License|BSD-2-Clause|
+|BSD 2-clause FreeBSD License|BSD-2-Clause-FreeBSD|
+|BSD 2-clause NetBSD License|BSD-2-Clause-NetBSD|
+|BSD 3-clause "New" or "Revised" License|BSD-3-Clause|
+|BSD 3-clause Clear License|BSD-3-Clause-Clear|
+|BSD 4-clause "Original" or "Old" License|BSD-4-Clause|
+|BSD Protection License|BSD-Protection|
+|BSD with attribution|BSD-3-Clause-Attribution|
+|BSD-4-Clause (University of California-Specific)|BSD-4-Clause-UC|
+|GNU General Public License v1.0 only|GPL-1.0|
+|GNU General Public License v1.0 or later|GPL-1.0+|
+|GNU General Public License v2.0 only|GPL-2.0|
+|GNU General Public License v2.0 or later|GPL-2.0+|
+|GNU General Public License v3.0 only|GPL-3.0|
+|GNU General Public License v3.0 or later|GPL-3.0+|
+|GNU Lesser General Public License v2.1 only|LGPL-2.1|
+|GNU Lesser General Public License v2.1 or later|LGPL-2.1+|
+|GNU Lesser General Public License v3.0 only|LGPL-3.0|
+|GNU Lesser General Public License v3.0 or later|LGPL-3.0+|
+|GNU Library General Public License v2 only|LGPL-2.0|
+|GNU Library General Public License v2 or later|LGPL-2.0+|
+|Fair License|Fair|
+|ISC License|ISC|
+|MIT License|MIT|
+|No Limit Public License|NLPL|
+|OpenSSL License|OpenSSL|
+|X11 License|X11|
+|zlib License|Zlib|