preparing 0.2-Release: added login-dialog, opening up installation.

Features:
- dm's read_requires_login can now be set to false
- changed some style-definitions
- support for adressing thematical timelines with many tags like: "/notes/tagged/tag1+tag2"

Fixes:
- decode tag-names entered via url properly

Pending:
- current layout currently does explicitly not support IE9, IE10 and Opera
- MathJax-Editing needs robustification

Note:
Installation depends on DeepaMehta 4.1.1-SNAPSHOT as of commit:
ca61964a27e6757848e638c3bafc9374c6aff45c

Documentation:
https://www.eduzen.tu-berlin.de/software-komponenten (German)
https://www.eduzen.tu-berlin.de/zur-notizen-webanwendung (German / Get User Account)