Fixed debian init script

- Previously did not source /etc/defaults/jmxtrans correctly as the
  runcommand is a bash script and as such was not inheriting the sourced
  variables. Fixed it by making the source export with `set -a`
- Made $RUNCMD point directly to the script. Previously it was a line of
  bash which would also fail to source defaults and give the wrong exit
  code on failure to find the script (127 instead of 2)
Merge pull request #112 from Stackdriver/master

Use typeNames when provided in config for StackdriverWriter
Used @PACKAGE@ variable in path
Corrected run directory for daemon
Merge pull request #113 from oholiab/master

Fixed debian init script
Preserve the current environment in jmxtrans.sh
Should fix #113 - https://github.com/jmxtrans/jmxtrans/pull/113#issuecomment-33805234
Add a header description
* Touch and chmod pidfile. jmxtrans user does not have permissions to write pid file @ /var/run/jmstrans.pid
* Load /etc/default/jmxtrans at last position, ie *after* setting some variables
* Introduce JMXTRANS_USER and JMXTRANS_GROUP
Merge pull request #115 from obazoud/stop_status_load_etc_default

Preserve the current environment in jmxtrans.sh call
Merge pull request #117 from obazoud/debian_init_doc

Add a header description
Merge pull request #118 from obazoud/pid_file_permission

* Touch and chmod pidfile. jmxtrans user does not have permissions to wr...
Enabled setting of debian package version

- Means that package build can be iterated on and dpkg versions can be
  changed without modifying the upstream version number
- Version can be specified with -Ddeb.version
- Will still default to "1" to preserve old behaviour
Merge pull request #119 from oholiab/master

Enabled setting of debian package version