Fix building systemd unit files

The previous Makefile rule would generate all unit files from
`redshift.service.in`. This is fixed to generate the file from the proper
`.service.in` file.
Merge pull request #92 from jonls/fix-91-makerule

Fix building systemd unit files
Fix #90: Print N/S and E/W in the location
Fix #105: Limit decimals in displayed location to two
Fix: desktop files missing in EXTRA_DIST and CLEANFILES
Add gamma-dummy.c to POTFILES.in
configure.ac: Fix undefined GETTEXT_PACKAGE on install
Fix #114: Update nl translation
Added intltool to dependencies, as I got errors on ./bootstrap without it
Merge pull request #116 from emilf/master

Added intltool to dependencies, as I got errors on ./bootstrap without it
Add Travis CI configuration file
README: Rename to README.md
README: Add build status image
README: Fix markdown syntax
Fix #112: Do not buffer lines from child indefinitely
redshift-gtk: Forward errors from child to stderr

This requires that the stderr (and stdout) are emptied when the
child process exits, otherwise redshift-gtk will exit before the
error output is forwarded. Also, the '-v' parameter is moved to
the beginning of the command line to avoid error output including
this (e.g. `redshift-gtk -l` would complain about the missing
location provided `-v`).
Update Travis CI script to run make distcheck
Add a note about Ubuntu dependency packages

...which can be found in .travis.yml
Merge pull request #139 from khink/master

Add pointer to .travis.yml for Ubuntu dependency packages
redshift-gtk: Relay USR1 signal to redshift process

This also adds SIGINT to the signals handled by redshift-gtk.