Implicit creation and deletion of local collections

[dilyanpalauzov]

I want to create on the server collections and synchorize them one way to the client. When on the server a new collection is created vdirsyncer creates it without asking questions. When on the server a collection is deleted, vdirsync discover removes the local copy.

• Add option to the configuration file or on vdirsync discover invocation, that creates locally collections, that exist on the server
• Add option to the confguration file or on vdirsync discover invocation, that deletes a local collection if it does not exist anymore on the server and the server has not returned temporary error

[dilyanpalauzov]

Moved to #869.