Expandeded part about different proc call syntaxes.
Fix optarg() and added two more tests.

One for 'do notation' in a single function in an expression, another the trick of using the method call syntax to pass two parameters.
Remove spurious import added in the last commit.
macro tests almost green
updated todo.txt
Merge branch 'devel' of https://github.com/Araq/Nimrod into devel
Merge pull request #865 from ReneSac/devel

Additions to the language manual and tests of new procedure call syntax.
Merge branch 'devel' of https://github.com/Araq/Nimrod into devel
added good error for stuff like string[int] or int[int]
deleted assert that would never fire because it turned into an error message
Merge pull request #870 from barcharcraz/templaterr

Added better error messages for ill-formed generics