Add template support to the network widget.

Allow users to choose how to display network information in a
backwards-compatible way.
[NetMonitor] Commentary and warning cleanup
Start a changelog for the next release
[CommandRunner] Add a new widget

This widget periodically runs commands and displays the output in a text widget.
[CPUInfo] Add a function to get CPU temperature
Add the command runner widget to the changelog
Reduce wakeups by tweaking RTS options

Found with the prompting and help of Joachim Breitner
[Command Runner]  Cleanups

Use a function from System.Process instead of re-implementing it.  The
only difference between this and the original is that stderr from the
subprocess is buffered.  This probably isn't a big deal since most uses
of taffybar would hide stderr anyway.
Use enclosed-exceptions to catch all notification errors
Support line graphs

This fixes #87.
Use @ in haddock comments
Have some default graphDataColors

So that people actually see something when they use the
defaultGraphConfig. The colors can probably be improved.

The use of an infinite list here is justified: We are always passing it
to a `zip`-like function which will only use as many as there are data
values provided by the user.
Draw the graph frame pixel-crisp

With cairo, if you want to draw a one-pixel-wide line, you need to put
the coordinates in the middle of the pixels, hence the -0.5 and +1.
New Graph option: graphBorderWidth

The main purpose of this is to be set to 0 to disable the border. But
who knows, maybe someone likes thicks borders...
Also make the vertical bar widget border pixel-exact
Merge branch 'master' of git://github.com/nomeata/taffybar into nomeata-master
Remove commented-out code
More thorough exception handling

This change uses the enclosed-exceptions package to run user-provided
callbacks safely, catching (and ignoring) all generated exceptions.
Compile with gtk 0.13 (and 0.12)

Fixes #89

gtk 0.13 seems to require ghc 7.8 (which is fine)
Prepare for a release