[FIX] #6 fix filesystem listfiles + file read buf

- Fixed file read to binary buffer
- List files now searchs in packs also
- Fixed StringRef compare operators
- Added startsWith, endsWith string utils
[UPD] #6 fix foreach auto reference
[FIX] #6 fix load files from zip

Zip files opens once on startup and closes on shutdown
[NEW] #6 add resource manager

All content must be loaded by resource manager. Every resource type must
be registered and can be preloaded by type or by manifest (list of
preloading resources).