Relax version requirements to accept a greater version

Fixes #104
Merge pull request #154 from devbliss/feature/clear-site-directory-option

Clear site directory before build
Merge pull request #130 from d0ugal/relax-requirements

Relax version requirements to accept a greater version
Fixed wrong order of media files copy from theme dirs (own, base -> base, own) to prevent own files being overwritten by their base counterparts
Merge remote-tracking branch 'upstream/master' into bug/incorrect-theme-dir-order

Synced with upstream
Merge branch 'bug/incorrect-theme-dir-order' into feature/format-url-option

Merged bugfix