Merge pull request #1 from bcipolli/local_content_tools

Local content tools
Tons 'o tweaks, plus reconfigure building nodes

Conflicts:

	kalite/management/commands/integrate_local_content.py
	kalite/shared/topic_tools.py
	kalite/shared/videos.py
	kalite/utils/general.py
Merge branch 'lex_crossmerge_1' into local_content_tools

Conflicts:
	kalite/shared/i18n.py
	kalite/shared/topic_tools.py
	kalite/shared/videos.py
Fixed a few issues that were introduced via all the new changes
Merge branch 'ben_tools' into local_content_tools

Conflicts:
	kalite/main/management/commands/integrate_local_content.py
Fixed bug in kind_by_extension and added ability to remove content
Ensure filenames being imported are unique.
Local content shares content root now
Tweaks to allow updating, specify type
tweak paths to work for all topic trees