import libtre and use it as a regex.h replacement

on Windows we do not have a regex.h header. libtre is a minimal regex library
with a BSD license which gives us the desired functinality.
Use it for gt_grep().
Windows: make signal functions work
silent clang warning
Merge pull request #131 from gordon/tre

import libtre and use it as a regex.h replacement
add reseting and accessing functions to kmeriterator

Conflicts:
	src/match/sfx-mappedstr.c
add help comments
change handling of edit operations

add documentation
add tools and classes for reference based genome compression
added compressed representation of edit script

needs cleanup
Merge pull request #129 from Garonenur/ole_final

Ole Eigenbrod tool
add '-seed' option to testsuite.rb
Merge pull request #132 from satta/seed

add '-seed' option to testsuite.rb