This is part of the process of making compiledata.cpp independent
of espeakedit.

This moves the libespeak source (*.cpp) files to src/libespeak-ng
and renames the C files (libespeak, espeak, speak) so they have
a .c file extension.

The libespeak files are supposed to be C code, so use C linkage
for all the functions defined in that code when they are being
referenced in the C++ code (i.e. espeakedit).

StdAfx.h is only needed for Microsoft Visual Studio C++ projects
that specify the "use pre-compiled headers" setting.

Some language files added/modified to synchronize with other sources