Fix some lintian errors and warnings

I fixed some errors and warnings reported by lintian. It is important that the .deb pacakge be free from lintian errors and warnings if you want it to be in the Debian archive. I also set the urgency to low, since high is reserved for releases that fix critical bugs (and as this is a first release, that makes no sense).

Feel free to change the long description. It can probably be made better.

Stuff really doesn't belong in the /usr/local directory. That is for system-wide stuff installed by the administrator instead of via a package manager. I fixed most of the errors relating to that, but not the logs, db, and backup stuff, because I wasn't sure where to put them.

The copyright file is missing.

You should use the appropriate package instead of including JQuery with OpenBazaar.

There is an extra license file (usr/share/openbazaar/pysqlcipher/LICENSE). All copyright information should be in the copyright file.

You have a bunch of stuff in usr/share/openbazaar/{html, node}/ set to executable when it should not be (like images, js, css, etc.).

Is there a particular reason the arch is set to amd64?

If you want to use lintian, you can run lintian file.deb to just get errors or warnings, or lintian -EvIL +pedantic file.deb to get everything.