Replaced all license headers with unified layout
max_connections is an integer field, not string

Currently the WebUI shows a warning complaining that e.g. 100 is not an
integer when trying to save the proposal with a different value. So the
max_connections attribute can not be changed.
Merge pull request #90 from tboerger/feature/license-header

Replaced all license headers with unified layout
Merge pull request #91 from mapleoin/max-con-integer

max_connections is an integer field, not string