[libmicrohttpd] Need --disable-examples

[Ken Bass]

For some reason I thought it worked at one point, but the configure 
script could use a working --disable-examples option.
If I recall, the examples do not properly build on different platforms. 
For example, if --disable-epoll is specified, it still tries to build 
examples that use epoll.
Other failures I recall are demo.c failing with an undeclared 
MAGIC_MIME_TYPE. There may have been others, but recently I have just 
been resorting to hand editing the src/Makefile to remove examples from 
the SUBDIRS variable, but I thought I would report this.

Thanks