Changed NULL coalesce from ?? (grokability#6353)

PHP 5 does not have the double question mark null coalesce support.

Fixed PHP warning Undefined offset: 1 in upgrade.php

Bumped version

Bumped version

Merge branch 'develop'

# Conflicts:
#	config/version.php

Merge branch 'develop'

# Conflicts:
#	config/version.php

Merge branch 'develop'

# Conflicts:
#	config/version.php

Merge branch 'develop'

Merge branch 'develop'

# Conflicts:
#	config/version.php

Merge branch 'develop'

# Conflicts:
#	config/version.php