Patch to fix build on some embedded targets/architectures

[Claas Anders Rathje]

Since I am trying to get the tool to work on some embedded systems (routers running OpenWRT) I started fiddling around a bit.

Prior submitting big changes I wanted to supply this patch against the current 3b8df63532b4 mercurial version.

It honors the CFLAGS and priviously set compiler and fixes a (on some architectures/libc combinations) big problem with the sscanf usage.

Maybe it will be merged or some others can benefit from the changes.