OPDS catalog: auto-fill http:// if no protocol given and revert #1106

This fixes #1259.
Merge pull request #1297 from Frenzie/language

OPDS catalog: auto-fill http:// if no protocol given and revert #1106
Merge pull request #1298 from Frenzie/master

Language: prevent spaces from disappearing in localizations with util.template
OPDS: ignore links with unknown rel values, treat empty rel as rel="subsection".
Merge pull request #1300 from erosennin/opds-ignore-unknown-rels

OPDS: ignore links with unknown rel values, treat empty rel as rel="subsection"
Add missing util.template definition to readerfrontlight.lua

Fixes #1302.
Merge pull request #1303 from Frenzie/language

Add missing util.template definition to readerfrontlight.lua