Merge pull request #3 from alinadubatovka/master

Refactoring =^_._^=
Small style fixes
Node.h and Entry.h temporary deleted
Node.h and Entry.h restored
Added tinyxml2

For future tests and benchmarks
leaf_entry stores void* instead of vector<void*>
directory .idea contains important information about project structure, e.g. libraries, that's why it is removed from .gitignore
Gist::search() is implemented, Entry::find() is added