* libs/common: refactor libs common 3
- move nil.go into types folder and make private
- move service & baseservice out of common into service pkg
ref #4147
Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>
* add changelog entry
* Remove deprecated PanicXXX functions from codebase
As per discussion over
[here](https://github.com/tendermint/tendermint/pull/3456#discussion_r278423492),
we need to remove these `PanicXXX` functions and eliminate our
dependence on them. In this PR, each and every `PanicXXX` function call
is replaced with a simple `panic` call.
* add a changelog entry
```
@melekes
yeah, bool is superfluous
@ethanfrey
If I remember correctly when I was writing test code, if I call Start() on a Service that is already running, it returns (false, nil). Only if I try to legitimately start it, but it fails in startup do I get an error.
The distinction is quite important to make it safe for reentrant calls. The other approach would be to have a special error type like ErrAlreadyStarted, then check for that in your code explicitly. Kind of like if I make a db call in gorm, and get an error, I check if it is a RecordNotFound error, or whether there was a real error with the db query.
@melekes
Ah, I see. Thanks. I must say I like ErrAlreadyStarted approach more (not just in Golang)
```