move all source files to src/
update .gitignore
update SDK
replace Botan with crypt_blowfish

Botan is just too much overkill
update licenses
massive code changes

these changes introduce syntax and behavior changes:
- it is now possible to specify custom callbacks + parameters
- no use of c++11 features, use of the boost libraries instead
- only one thread is used for hashing/checking
update .gitignore
added visual studio project files
added PAWN include file
updated makefile
fixed gcc compilation errors
replaced own implementation of boost::variant with boost::variant
fixed bug where an empty format specifier crashed the plugin
fixed OO design mistake
Minor tweaks
Use std::random on Windows, default to $2y$, add constant BCRYPT_HASH_LENGTH, update README
update license
update README