updated documentation
properly set error code
issue #564: better automatic mimetype detection for assets

also added possibility to override automatic detection with hard-coded value from manifest
added not-used code for localost->127.0.0.1
switched the order of FoxxManager & Foxx for didactic reasons
fixed some minor issues in arangob
some upgrade nodes
Merge pull request #594 from luebbert42/devel

switched the order of FoxxManager & Foxx for didactic reasons
updated documentation
Merge branch 'devel' of https://github.com/triAGENS/ArangoDB into devel
Merge branch 'devel' into unstable