Tests the execution of $parse()ed expressions. Each test tries to isolate specific expression types. Expressions should (probably) not be constant so they get evaluated per digest.

- Simple Paths
- Complex Paths
- Field Accessors
- Field Indexes
- Binary/Unary operators
- AND/OR short-circuiting operators
- Filters
- Function calls
- Assignment
- Object Literals
- Array Literals
- $watchCollection
- $watchCollection Literals