Fix screwed up list nesting in getopt's ddoc comment.
Fix std.string ddoc problems.

Fix missing parameters in ddocs for indexOfAny, indexOfNeither, etc..
Fix missing closing ')' which causes ddoc nesting error.

This should get rid of the warnings spewed by the compiler when building
the docs for `std.string`.
Fix missing $(RPAREN) in ddoc for std.random.uniform01.
Merge pull request #2407 from quickfur/random_ddoc

[dox] Fix missing $(RPAREN) in ddoc for std.random.uniform01.
Merge pull request #2405 from quickfur/getopt_ddoc

[dox] Fix screwed up list nesting in getopt's ddoc comment.
Merge pull request #2406 from quickfur/string_ddoc

[dox] Fix std.string ddoc problems.