dnsdist picks up cdb.h but can't link in the static archive.

/home/sk/tmp/openwrt/staging_dir/toolchain-mips_24kc_gcc-8.3.0_musl/lib/gcc/mips-openwrt-linux-musl/8.3.0/../../../../mips-openwrt-linux-musl/bin/ld: /home/sk/tmp/openwrt/staging_dir/target-mips_24kc_musl/usr/lib/libcdb.a(cdb_init.o): relocation R_MIPS_26 against `fstat' can not be used when making a shared object; recompile with -fPIC

This commit extends the tinycdb Makefile to build and install as well
the shared library as well as the pic archive. dnsdist will then pick
the shared library.

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

Currently tinycdb doesn't use {C,CPP,LD}FLAGS. This commit adds
MAKE_FLAGS to address this.

Before:

make[3]: Entering directory '/home/sk/tmp/openwrt/build_dir/target-mips_24kc_musl/tinycdb-0.78'
ccache_cc -O -D_FILE_OFFSET_BITS=64 -c cdb_init.c
cc1: note: someone does not honour COPTS correctly, passed 0 times
ccache_cc -O -D_FILE_OFFSET_BITS=64 -c cdb_find.c
...

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

fix Makefile chmod (644)
replace MD5SUM with HASH
add PKG_MIRROR_HASH when PKG_SOURCE_PROTO:=git

(PKG_SOURCE_PROTO:=svn tarballs are not reproducible for now)

Signed-off-by: Etienne Champetier <champetier.etienne@gmail.com>