Gerrit options: per-project

Currently you can have only one gerrit settings, and it is completely project-independent, so every time you want to apply from it you need to select root dir for local repo.

It would be really nice If we could save different gerrit settings for different projects. This can IMO be done two ways:

1 - with project, in pro.user file (or similar) - however it would be nice if these settings were preserved when you switch environment and another user file is created.

2 - if above is not possible, it would be nice to make gerrit settings similar to build confuiguration settings, where you have build configuration name, and you can change between different settings - something similar can then be done for gerrit so that you have gerrit configuration, and each gerrit configuration has all current options, plus one more - local repo (or project) path.

then when you nave a project opened and start gerrit, he shows correct configuration:

NOTE: consider git submodules - when user runs gerrit command he should have one file or project opened (otherwise - nothing happens).

if there is a file opened, get it's submodule path and work with it,
if there is no file, get current project path.