Fixes testserver with Python3.4. All files are now opened in mode, 'rb'.

Applied futurized to _browsermanagement.py with Drobota's patch.

Updated docs to v1.7.4

Updated docs

Merge pull request robotframework#457 from rtomac/1.7.2-release

Prepare for 1.7.2 release

Prepare for 1.7.1 release

Merge pull request robotframework#425 from zephraph/1.7-release

Update docs for 1.7 release

1.6.0 release

1.5.0 release

1.4.0 release