0.1.7 Released

The debug heap now correctly handles padding for arrays on certain platforms. Specifically, unit tests now pass on x64. Hashtable and list now copy constructor friendly. Fixed hang-bug in un*x thread start. Cleaned up the Thread class. RWLock complete. MSSQL and MYSQL code complete, but untested. On windows, chnage spl/configwin32.h to enable mysql. Moved Date.h to DateTime.h, which includes both Date and DateTime. Added String::Trim(). Fixed MySql build. SQL_TYPE_FLOAT8 changed to SQL_TYPE_FLOAT32.