Flexlibs

+ Added LexiconClearField()
+ Updated Set/Get Field functions to handle MultiStrings and a WS
parameter (fully backward compatible).

+ Added the DLLs needed to support FieldWorks 9.1.15/16
+ Added support for Texts to BuildGotoURL()

+ Constrained pythonnet to < 3 since flexlibs breaks with the new v3.0.0

+ FLExProject now requires a CloseProject() call to save data and
release the lock on the FLEx project.

+ Configured as a package and published on PyPI