Improve network performance for VirtualBox

Without those lines, VitrualBox machines are being very slow with all network operations (tested only in OS X Lion, but they are supposed to work everywhere). See https://github.com/mitchellh/vagrant/issues/1807
abord build if mergeConfig returns an error and fix duplicate error message
Add proper bash completion for "docker push"
use less reflection in command line method invocation
Merge pull request #2034 from metalivedev/1969-cherrypick-fixcommitformat

Fix #1969 formatting, add information about multiline json
Add test
add missing error check
added initial draft of the Docker infrastructure doc
Fix contrib/mkimage-debian.sh apt caching prevention
Insert popularity and boost docs results.
use empty string so TempDir uses the OS's temp dir automatically (Closes #2117)
Use correct auth config when logging in.
fix rm -v
Fix some error cases where a HTTP body might not be closed

Refs #2126
Swap contrib MAINTAINERS
Make sure to close the network allocators
Add devenvironment link to CONTRIBUTING.md
Fix #2115 Clean AUFS references. Also fixes some links to client libraries and mongo example.
Merge pull request #2134 from tianon/contributing

Add devenvironment link to CONTRIBUTING.md
Merge pull request #2130 from tianon/swap-contrib-maintainers

Swap contrib MAINTAINERS