Use a global variable instead. In SL, the optimizer does the replacement automatically, therefore no memory penalty is incurred. In OpenSim, the variable is assigned at run time with llUnescapeURL. The OpenSim separator is also changed from U+001F to U+007F, because most control characters under U+0020 cause problems with exporting when present in script memory.
Fixes#41.
Under Windows, 'del' was causing problems with the forward slashes used for directories, as these are not accepted by the shell commands, even if they are accepted as paths in general. Fix it by adding 'rm' capabilities to build-aux.py and using it in Makefile instead of the $(RM) macro.
