[SRU] ReText 2.1.6 bugfix release

ReText 2.1.6 is ready for uploading into precise-proposed. This is a bugfix-only release for ReText-2.1 LTS branch (current stable release is 3.0.4).

List of changes (full log from upstream Git: http://paste.ubuntu.com/1014665/):

[6c5d3d11ce] Re-add .re (ReText 1.x files) to the list of supported extensions
[0e98c1cf62] [HIGH] Don't crash if some extensions can't be loaded
[ba4ecece0e] Don't treat e-mail addresses as HTML tags
[d42266e943] Add German translation
[96d5ae4f33] [HIGH] Fix crash when trying to save file to read-only destination
[bf36863e90] [HIGH] Window close: don't continue when user pressed Cancel
[50abef0821] [CRITICAL] Make menu's Quit action ask for confirmation instead of simply closing the window

==Impact==
Affects all users. Commits 50abef0821 and 96d5ae4f33 fix bugs that could result in data loss (!) for some users.

==Development Fix==
All these fixes are applied in version 3.0.4-1 in quantal.

==Stable Fix==
A branch with SRU for precise is attached. Link to the upstream tarball: http://downloads.sourceforge.net/project/retext/ReText-2.1/ReText_2.1.6.tar.gz.

==Test Case==
Here are the test cases for commits marked as HIGH or CRITICAL:

0e98c1cf62:
1. echo "mdExtensions=notexistent" >> ~/.config/ReText project/ReText.conf
2. start ReText, it shouldn't crash

96d5ae4f33:
1. mkdir readonly
2. chmod -w readonly
3. start ReText, type something, try to save a file to "readonly" dir
4. it shouldn't crash/segfault

bf36863e90:
1. start ReText, type something
2. create a new document (Ctrl+N), type something there
3. click the window's close (or press Alt+F4), press Cancel in the popup dialog
4. another popup dialog shouldn't appear

50abef0821:
1. start ReText, type something
2. select "File->Exit" (or press Ctrl+Q)
3. the window shouldn't close, instead, a confirmation dialog should appear

==Regression Potential==
There shouldn't be anything that could cause regressions in this release.