Use standard sys.exit() instead of the fragile exit from site.py module
Merge pull request #29 from florentx/sys-exit

Use standard sys.exit() instead of the fragile exit from site.py module
Fix R install instructions
Generate stable output when running tests: patch localtime
Add stub file barchart.py to ensure stable output for filters-test.txt
Change utf8-bom-test.txt to generate stable output
Do not print the source-highlight version, it may differ between environments
Print the test version instead of the lib version to avoid rewriting expected output after each release