sensors-lxpanel-plugin updated from version 1.1 to v1.2 and other fixes

Hi.  Updated ebuild to version 1.2.  Additionally contacted author of program who has now tagged his builds v1.1, v1.2, etc.  Modified the ebuild to point directly to his github page and tagged version number.  Added use dependencies for lxpanel to metadata.xml as discussed with Golodhrim on IRC.  I think it's ready to go, pending a check.  Idling on IRC if you want to discuss it.  Hope another pull request was the right thing to do...