Feature/instrumentation filter

Two main features ended up in this branch:

**Trace Instrumentation Filtering**
The trace page now shows a 'trace' column. It contains checkboxes that let the user control whether or not a particular package (or virtual group) will be traced when they start a new trace. This allows users to upload an entire `.war` file to Code Pulse, but not necessarily have every single class found in that `.war` file get traced.

**Virtual Groupings for the Packages List**
The packages list now shows three main groups: "Classes", "Jars", and "JSPs". When uploading a data file for a new trace, class files are assigned to one of these groups;

 - `.class` files found directly inside the upload file are treated as "loose" classes, and added to the "Classes" group.
 - `.class` files found inside .jar files within the upload (e.g. `upload.war/some/dir/library.jar`) will be added to the "Jars" group.
 - `.jsp` files will be processed, generating a class entry that will be added to the "JSPs" group.