Add ability to skip auth in specific modes

The configurator knows the general active mode and exposes a function
to check for it.
It's also the only place to instantiate Auth instances.

Auth instances can now be configured with an array of `skipModes` -
modes where the authentication routine is circumvented.

The configurator passes the mode function to the Auth instance, so that
it can check if authentication is required or not.

Closes #458
Merge pull request #469 from latin-language-toolkit/auth_and_modes

Add ability to skip auth in specific modes
don't do an inventory lookup if the form doesn't have a lexInvLocation
Merge pull request #483 from latin-language-toolkit/lexinvfix

don't do an inventory lookup if the form doesn't have a lexInvLocation
Add lodash which can be accessed with _.
Add deselect button to tree.
Add tooltip.
Add angular ui utils
Extract tokenSelector directive
Fix wrong merge conflict resolution by deleting marked
Renaming
Display of debugging info
Fix checked logic
Just use one watch instead of many functions
Move selector to left

Tree controls and focus settings have wrong position.
First version of dropdown to select tokens
Update selected item according to selection changes
Hack to place settings and controls on the top right