DSL: add `tags` stanza

only limited/defined keys are permitted
 - :vendor
 - :font_pitch
 - :font_serif
 - :font_weight
 - :font_slant

forward-compatibility: no associated functionality is
provided.  Intentionally left undocumented.

References: #4688
Upgrade serf to 0.6.3
Add abgx360 app v1.0.6
Add phantomjs 1.9.7
Added Reaper 4.7 Cask

Reaper is a digital audio workstation software
Updated SourceTree to 1.9.5.2
Merge pull request #5312 from crainiarc/sourcetree

Updated SourceTree to 1.9.5.2
Update Tunnelbear to 2.4.2
Merge pull request #5313 from gabrielizaias/tunnelbear-2.4.2

Update Tunnelbear to 2.4.2
r 3.1.1
Merge pull request #5311 from stonerl/reaper

Added Reaper 4.7 Cask
Merge pull request #5310 from prisoner/phantomjs

Add phantomjs 1.9.7
Merge pull request #5308 from lalyos/master

Upgrade serf to 0.6.3
Update Cakebrew.app to v1.0.8
Merge pull request #5318 from koenrh/cakebrew

Update Cakebrew.app to v1.0.8
Upgrade Android Studio.app to v0.8.2 build-135.1267975
Merge pull request #5320 from tolbkni/android-studio

Upgrade Android Studio.app to v0.8.2 build-135.1267975
Merge pull request #5314 from sjackman/r

R 3.1.1
Update Hydra to 0.13
Merge pull request #5321 from ndr-qef/hydra

Update Hydra to 0.13