Fix Android cross-compiling issues

-Use stdlib.h for memcpy/memset
-Hardcode lconv->decimal point to '.'
-Doing an install will now just move the headers.  Doing a make will build the
libs and output them in the appropriate location.  This way, you can make
install on any one platform, and make for all the others (since you only really
need a single copy of all the headers.