minor string fixes

- added STR_ZOMBIE to English.lng, EnglishUk.lng, Russian.lng, German.lng
- fixed a few alien names in Russian.lng based on ufopedia.org usage
fix sign comparison warning
github doesn't think tabs are 4 spaces :(
don't stealth-change TU reserve from Auto to Snap

Fixes this problem: With time units reserved to autoshot, if a soldier with a
non-auto weapon ran up against the snap shot TU reserve limit, _tuReserved
would be permanently set to BA_SNAPSHOT. As a result, all subsequent soldiers
with auto weapons would actually erroneously reserve TU for snap shots.
Merge pull request #258 from hmaon/clean

added STR_ZOMBIE to several .lng files, fixed several Russian strings, fixed my code formatting, a compiler warning, and a TU reserve bug