Stopping non-linear terms from entering the dio solver. Fixes bug 547.
Merge branch '1.3.x'
Merge branch 'master' of github.com:CVC4/CVC4
portfolio: add stat to track time spent waiting for interrupted threads to stop
String parsing example in CVC parser
add negative int2str
hot fix for str2int/int2str
Merge branch 'master' of github.com:tiliang/CVC4

Conflicts:
	src/theory/strings/theory_strings_preprocess.cpp