New feature, bug fixes, refactoring

New feature:

• When creating a new requirement area do not show color options already in use

Bug fixes:

• Description changes of requirement area items are not synchronized with other users having the same item selected, fixed
• When removing an item in the product overview with dependencies or conditions on its descendants, these are not recovered on the undo, fixed

Refactoring:

• Sign out refactored app wide to prevent the listenforchanges longpoll to continue after sign out
• Move global functions to helpers module
• Redundant entries in package.json removed