More chpldoc updates to modules/standard/Random.chpl
More chpldoc updates to modules/standard/Random.chpl

With Lydia's latest chpldoc improvements, my top-2 CHPLDOC FIXME
issues are closed (so removing the comments related to those).  In
reviewing the output, two others came up, though, making my new top 3:

* for arguments of unknown/generic type with default values, we
  should render 'x = y' rather than 'x -> = y'

* in general, I think we should render type qualifiers as ':' rather
  than '->' to be consistent with Chapel concepts.

* (holdover): have chpldocs follow module declaration order.

CoryMcCartan/chapel,hildeth/chapel,chizarlicious/chapel,chizarlicious/chapel,hildeth/chapel,chizarlicious/chapel,chizarlicious/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,chizarlicious/chapel,hildeth/chapel,chizarlicious/chapel,chizarlicious/chapel,hildeth/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,hildeth/chapel,hildeth/chapel,hildeth/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel