Snowfakery

Add child_index feature for calculating the index number of each child object (see documentation for more information).

Internal changes to support upcoming features in CumulusCI.

Documentation for the Math plugin.

Dates can now be parsed from strings with the `date()` function. (see docs)

Added `relativedelta()` function. (see docs)

Official formula syntax is now ${{foo}} instead of `<<foo>>`.
The old syntax will be supported for at least the remainder of 2020.

Docs are checked into Git in Markdown format.

Official terminology changed so that Snowfakery files are now called "recipes".

Stabilize the output order for CCI Mapping files generated by Snowfakery.

New syntax for Internalized fake data. (see docs)

Internally use the plugin architecture to support even the builtin functions.

Snowfakery includes support for Salesforce RecordTypes.

Snowfakery can output SQL/JSON NULL using YAML blank fields or the YAML literal 'null'

Fields starting with \_\_ are now properly suppressed as per the documentation.

Various performance and reliability improvements:

- parsed dates are now cached
- Jinja values are always coerced to a string where appropriate
- internal attributes were renamed for clarity
- lookups are only generated in CCI mappings if they are actually needed

Snowfakery now specifies its install requirements with minimum versions rather than specific versions,
for improved compatibility with CumulusCI.

Windows compatibility improved, especially in test cases.

Changed the syntax for CSV handling.

Added --output-folder command.

Bugfixes (not user visible) and code cleanup.