Rename states for consistency; upgrade gems

Squashed commit of the following:

commit ffab6909ab4c31e2d650405db45453a7572ab007
Author: Thomas Schank <DrTom@schank.ch>
Date:   Sat Dec 6 12:52:05 2014 +0100

    Fixex

commit 53fa2096cb7480b8db3fd960439e68c4053cb4e3
Author: Thomas Schank <DrTom@schank.ch>
Date:   Sat Dec 6 10:39:24 2014 +0100

     ...

commit 2e29b72298dbe3486e8d0623be864ed3ecf12f82
Author: Thomas Schank <DrTom@schank.ch>
Date:   Sat Dec 6 10:37:17 2014 +0100

    ... adjust task select conditions ...

commit 681da0d0f35b111f299a7753875c6dffc96fe14c
Author: Thomas Schank <DrTom@schank.ch>
Date:   Sat Dec 6 10:23:17 2014 +0100

     ... views ....

commit 931da01bba72bc93615d12276872b2a6df3ede38
Author: Thomas Schank <DrTom@schank.ch>
Date:   Sat Dec 6 10:18:54 2014 +0100

    ... helpers ...

commit f41335aa25c694bbdfe2c5d2e2eba23d33732d33
Author: Thomas Schank <DrTom@schank.ch>
Date:   Sat Dec 6 10:17:30 2014 +0100

    ... controllers ...

commit 0f1af6a8739ccf4875e989610ac67a9f4c577b8b
Author: Thomas Schank <DrTom@schank.ch>
Date:   Sat Dec 6 10:15:36 2014 +0100

    ... models ...

commit 23d0ff37d2bd0c7b0fb15bac34364084f77f6dc1
Author: Thomas Schank <DrTom@schank.ch>
Date:   Sat Dec 6 10:13:14 2014 +0100

    Consistent states "success" -> "passed" ... migration ...
Add public view possibility, improve badges, enabled css themes

* add public view possibility for executions and related resources
* provide named redirects for executions and attachments
* clean and generalize stylesheets and thus enable themes
* badges don't rely on external stylesheets (conditionally)
* show attachments within iframe (including link to original resource)
Use a different approach to disable triggers temporarily

(which doesn't require superuser privileges)
Sass: refactor and make more themeable

  - sass: put partials in lib/{.,mixins}
  - document and make themeable
  - add example themes: 'flatly' and 'darkly' from bootswatch

Squashed commit of the following:

commit 5af8d680ff4cdf4ff98beae6e8e156b6045a206b
Author: Max F. Albrecht <1@178.is>
Date:   Sat Dec 13 19:11:21 2014 +0100
UI Fixes

Conflicts:
	app/assets/stylesheets/lib/executions_table.sass