* Supports tags when comparing commits or branches

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Hide headline when only comparing and don't load unused data

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Merges compare logics to allow comparing branches, commits and tags with eachother

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Display branch or tag instead of commit when used for comparing

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Show pull request form after click on button

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Transfers relevant pull.go changes from master to compare.go

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Fixes error when comparing forks against a commit or tag

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Removes console.log from JavaScript file

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Show icon next to commit reference when comparing branch or tag

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Updates css file

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Fixes import order

* Renames template variable

* Update routers/repo/compare.go

Co-Authored-By: zeripath <art27@cantab.net>

* Update from master

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Allow short-shas in compare

* Renames prInfo to compareInfo

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Check PR permissions only if compare is pull request

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Adjusts comment

Signed-off-by: Mario Lubenka <mario.lubenka@googlemail.com>

* Use compareInfo instead of prInfo