Output supervision template as application/zip so student can download template for a particular supervision

[MatthewIreland]

Hook up the generation code that Ananya wrote to Tomcat.

For now, use hardcoded supervision parameters. Return application/zip stream to student when they go to a particular link.

[John-Fawcett]

Steps:

• read template files
• find/replace {{SV_DATE}}, {{SV_TIME}}, etc. with appropriate values
• return all template files inside a ZIP file, created with a ZipOutputStream.

Get "appropriate values" by loading the SV record from the database. Primary key (to know which SV you're talking about) will come from URL query parameters (...?foo=bar&foo2=bar2&...)