0.2.1
fix release version and Makefile.am substitutions; 0.2.1 release
[module] rework module code to its own file with cleanup and docs
[all] rework to properly support the verto_default() singleton behavior
fix some style issues: wrapping and void usage
[module] documentation updates
[core] add pthread locking support around the global state
[core] make verto_reinitialize() have a return value