Added variables for thread local storage
Added key_create
Added pthread_key_delete
More todo based on xpress notes
Began changing tls functions to use new structures
Outlines for most tls functionality, commented out to work on bug
Working on bug
Usually works but sometimes throws exception
Little bit of documentation
Possible error with master branch
Fix thread local storage example
Changed memory allocation of tls_key
Added destructor calling, modified thread_local_storage example to demonstrate
Merged in thread local storage