Fix schema URLs
Add coverart archive mbdump
Fixe the MySQL backend for the current schema:
- backend_mysql_load_data: Import coverart tables in a similar fashion to what we currently do with statistics tables.
- backend_mysql_update_schema_from_file: Support CREATE TABLE queries that doesn't end with "\n);"
- backend_mysql_update_schema_from_file: basic support for Postgres POINT fields (dummy mapping to VARCHAR(100))
- backend_mysql_update_schema_from_file: Map Postgres TIMESTAMPTZ datatype to MySQL TIMESTAMP.
- backend_mysql_update_schema_from_file: [Debug] Print what column is currently being added
- backend_mysql_update_schema_from_file: Ugly hack for ignoring CONSTRAINTs on CREATE TABLE that span multiple lines (checking if second word is "OR"/"IS"/"=", or if parsing yield a bracket as a field name).