Changes due to boost locale:
- Updated README.linux
- Fixed missing boost locale include when compiling with unit tests
- Updated RPM spec (increased minimum boost version, added boost locale requirement)

git-svn-id: http://svn.code.sf.net/p/vcmi/code/trunk/@3599 4dfc6b2a-8b31-0410-aa91-d6c70e3ac834