Adding additional filetypes to ProjectPier

When uploading files to a project it's nice that the system identifies the file type and shows the corresponding icon for the file.  We upload Word documents as well as PDF versions, so our clients can quickly choose the version that's most appropriate for their need.

ProjectPier 0.8.6 ships with a bug in its SQL load that sets "xls" files to "xsl" as the extension and "doc.png" as the icon.  It's also missing newer "xlsx" and "docx" types.  These things are easy to fix from the MySQL shell.

mysql> insert into pp086_file_types (extension, icon) values ('docx', 'doc.png');
Query OK, 1 row affected (0.00 sec)
mysql> update pp086_file_types set extension='xls', icon='xls.png' where extension='xsl';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0
mysql> insert into pp086_file_types (extension, icon) values ('xlsx', 'xls.png');
Query OK, 1 row affected (0.00 sec)