[ticket/305] Add fetch_posts service as replacement for phpbb_fetch_posts

B3P-305
[ticket/305] Mark phpbb_fetch_posts() as deprecated

B3P-305
[ticket/305] Only run coveralls on PHP 5.5 and mysqli

B3P-305
[ticket/305] Make run-coveralls.sh executable

B3P-305
[ticket/305] Reduce complexity of set_forum_constraints()

B3P-305
[ticket/305] Simplify method get_global_id()

B3P-305
[ticket/305] Use fetch posts service in news and announcements modules

B3P-305
[ticket/305] Split up get_type_constraints()

B3P-305
[ticket/305] Add method for running sql query

B3P-305
Merge pull request #306 from marc1706/ticket/305

[ticket/305] Turn phpbb_fetch_posts into service