Simplify ScheduledC Interface

[JCampbellBradley]

Currently, the ScheduledC interface is very messy, with many 'optional' objects required by the signature, and with all options being represented as individual boolean arguments.

I propose we

1. consolidate all of the options into a 'CodegenOptions' object,
2. only require the essential objects (i.e. the system body and scheduler) when instantiating ScheduledC. The other objects (memory mapper, tiler, etc.) should be initialized in a default manner (i.e., the memory mapper will be initialized to an identity map). These objects can then be manually specified with methods prior to codegen, if one desires a custom memory map or tiler or whatnot.