Complete parsing of RG in implicit ops.

[Issue 344]
Add SOperation level assistant class.

Includes initial method for constructing implit rely func.

[Issue 344]
Call type checker on RG nodes of implicit ops.

[Issue 344]
Clone relyCondition body when building relyDef.

[Issue 344]
Check type of RG bodies when type checking RG defs.

Was previously TCing the postDef body. oops.

[Issue 344]
Build rely_op for implicit operations.

[Issue 344]
Add RG conditions to operation toStrings.

[Issue 344]
Type check RG in explicit operations.

[Issue 344]
Build rely_op def for explicit operations.

[Issue 344]
Complete SOperationAstnt to make RG defs for both kinds of ops.

[Issue 344]
Construct guard defs for imp and exp operations.

[Issue #344]