addons: support for URI's containing ~ and +

[glitsj16]

Better current word selection for URI's containing ~ and/or +. By adding ~ and + to GEANY_WORDCHARS URI's from launchpad.net (and others) get selected (and opened) correctly. Otherwise these get cut at the tilde character.

Example: https://launchpad.net/~geany-dev/+archive/ubuntu/ppa gets selected as https://launchpad.net/

[eht16]

The changes look fine to me. Only a more descriptive commit message would be cool.

[glitsj16]

Updated descriptive commit message.

[b4n]

@glitsj16 you only updated the PR's title, not the commit's message :) To update the commit message, use git commit --amend, and then replace the commit on this PR with git push -f glitsj16 master.
BTW, tip: next time, don't commit on branch master, always create a separate branch to work on some changes (git checkout -b my-feature-branch), as this will prevent your own master from diverging from geany-plugins's master.

Otherwise, LGTM

[b4n]

replaced by #239