Module did not have an uninstall, so the variables still stayed in the database. Added .install file with uninstall.

#278220 by sigsby: The variable used to store the url for past campaigns is lowercased (campaignmonitor_pastcampaignurl) while the call to variable_get() has it camel-cased (campaignmonitor_PastCampaignURL).

Also removed some uneccessary testing watchdog calls.

Update module to work just as well without the profile module installed as with. Check if it is installed and act accordingly.
Also removed some unneccessary comments.