package.json: bump dev deps to actual state
jshintrc: removed prop that is turned on by default now
2 minor improvements for grunt-properties plugin

They are:
1. support of nested keys (eg "level1.level2.key")
2. build into plain hash/map without assignment
grunt-properties: new tests and stuff around it
Merge pull request #3 from ZuBB/nested_keys

Nested keys