Adds missing 'ToPatterns' identity instance
Adds pattern~>patterns promotion instance
Removes intermediate data-structure of patterns

- Reimplements '&','&=','&~','|>' and '|$' directly as regular functions
  instead of as data constructors and instances.
Merges all simple patterns into /Pattern
Simplify definition of channel patterns
Fixes haddock parse errors, adding documentation

- Fixes haddock parse errors, in particular removing
  unsupported GADT comments

- Adds inline source to examples documentation.