Remove unsigned changes for >= 0 (clang warning)
Add swig/copywhich.sh to the dist.
swig: Use alloca() to reserve stack variables used in typemaps.

Otherwise, swig sometimes places variables inside scopes, and
retaining pointers to these variables causes problems.
Merge remote-tracking branch 'steve/master'
Fixed segfault storing/retrieving single strings as static props e.g. units.