Add support for msgmerge --no-fuzzy-matching

msgmerge creates fuzzy entries by default when it sees similar entries
in the "old" version of the file. This is helpful when there's only a
small modification to a string, but on the other hand, it can cause
problems with less experienced translators who accept fuzzy entries
without really checking.

Use --no-fuzzy-matching flag to disable this (and have better
performance), optionally. Bind the behavior to "Consult TM when updating
from sources". It is similar enough to TM updates to make sense, and it
avoids adding yet another setting (to be revisited if there are
complains about this).
Fix crash when clicking "Don't show again"
Skip OS X sandboxing code when not sandboxed
Detect file wrapping and apply it when saving

Detect line wrapping setting used to create the PO file and preserve it.
This allows handling --no-wrap files nicely, as well as preserving
non-standard column widths. Still use the default for new files.
Only preserve file wrapping if not disabled

Reuse the existing keep_crlf setting and only preserve file's wrapping
if the setting is on (the default). Change its UI label to reflect that
it no longer affects only line ending characters, but also line endings
wrapping.
Detect file's line endings when loading, not saving

Remember line endings of the file as it was loaded and preserve it when
saving (if so configured). Previously, Poedit would look at an existing
file being overwriten when saving and use its line endings. That was
both less efficient and not quite logical.
Make wrapping configurable in preferences

Make it possible to enable/disable wrapping of PO files and set wrap
width in preferences. The default is to use gettext defaults (wrap at
column 79) and to preserve edited file's settings.
Merge branch 'proper-line-wrapping'

Fixes #94.
Fix saving files with Windows line endings

This resulted in mixed line endings because msgcat couldn't handle CRLF
input well. Fix this by always outputting with Unix line endings for all
gettext tools and only convert to CRLF if requested by the user.
Don't bother with TM suggestions if the language isn't set

There wouldn't be any useful hits anyway.
Update wx to fix wxStaticText disabling on OS X

Relevant commit 6d2d09327df021035b1f67ad130fe2d7c9909f9e:

Fix wxStaticText::Disable() to respect text color on OS X

wxStaticText emulates disabled state on OS X by changing text color to
light grey. When re-enabling the control, though, it always set the
color to the standard text color, which broke static texts with a custom
color.

Fix this by keeping track of the original color and restoring it back
when setEnabled:YES is called.
Don't use icon in progress info window
Remove unused accidentally duplicated code
Don't use gray for ExplanationLabel under GTK+

Inconsistent with native use.
Fix missing Show Sidebar menu item under GTK+
Provide convenience Suggestion ctor.

Also fixes gcc warning about uninitialized source field.
Fix Ctrl+Shift+arrows accel under GTK+

This accelerator was broken by allowing multiple selection. Fix it by
explicitly listing these shortcuts in the global accel table, together
with other Ctrl+ accelerators.
Fix setting fonts on OS X

Clicking the checkbox would cause saving preferences _before_ the face
was sent, in which case SaveValues() saved it as unchecked (because the
font was invalid). Then when the user clicked to change the face, a
modal window shows up and when dismissed, the generated activate event
would cause _loading_ of preferences, where the checkbox was saved as
off. This was "only" a problem when setting custom font initially, i.e.
in the common case.

Fix by always having some valid font in there.
Better phrasing of missing spellchecker prompt

Don't tell they user that they "have to" do something. Also show the
language in a more natural form, instead of the full locale name of
Language (Country, Variant).