New branch nwellnhof/compiler_flags

[Nick Wellnhofer]

I think it's about time that we remove the dependency on Perl5's $Config 
hash in Parrot's configure system. I started with a new branch that 
changes configure to explicitly set all the compiler and linker flags 
without using Perl's config.

I only tested it with Linux. I tried to deduce the needed compiler flags 
for all other platforms from the output of some Smolder reports but I'm 
not sure I got it right. It would be nice if the branch could get some 
testing on Darwin, BSD, Solaris, Windows/MSVC, Cygwin, MingW32, etc.

The remaining things read from Perl's $Config hash are

- the default compiler, make and some other tools
- some i_* header flags
- archname
- d_socklen_t
- osvers
- scriptdirexp
- sig_name
- sPRIgldbl
- things I might have overlooked

Nick