Merge branch 'release/4'
Bumps version numbers for development version. Refs #25.
Updates release steps. Refs #25.
Updates logic submodule. Refs #29.
Uses n_global.nim from logic submodule. Refs #29.
Updates build script clean targets' paths. Refs #29.
Moves more objc to logic submodule. Refs #29.
Uses new NSStringFromClass wrapper. Refs #29.
Casts unsigned to signed to avoid warning. Refs #29.
Documents task in changes log. Refs #29.
Merge branch 'feature/t29_refactor_common_code'
Modifies syle for help screens. Refs #30.
Documents task in changes log. Refs #30.
Formats dates in relative format. Refs #31.
Removes hyperlinks from appstore changes log. Refs #31.
Updates logic submodule. Refs #32.
Updates nimcache paths to compile project. Refs #32.

Recent compiler changes filename scheme, see
https://github.com/Araq/Nimrod/issues/852.
Alternates weight cell backgrounds. Refs #32.
Shadows same date strings with lighter color. Refs #32.
Scans external logic submodule for ctags. Refs #32.