Refactored take_unwrap (libstd/option.rs)

Using pattern matching instead of is_some + unwrap
Asked if missing (), then asks about an anonymous function. Also added test.
getopts missing docs
auto merge of #12931 : aochagavia/rust/option-take_unwrap, r=cmr

Using pattern matching instead of is_some + unwrap
Add method Vec<T>::as_mut_ptr()
Document the Tm struct and fields
Doc-sprint: Document endian conversion functions
auto merge of #12937 : sinistersnare/rust/method-error-message, r=huonw

its a common (yet easily fixable) error to just forget parens at the end of getter-like methods without any arguments.

The current error message for that case asks for an anonymous function, this patch adds a note asking for either an anonymous function, or for trailing parens.

This is my first contribution! do i need to do anything else?
auto merge of #12940 : cadencemarseille/rust/time-doc, r=alexcrichton
auto merge of #12942 : alan-andrade/rust/docathon-getopts, r=alexcrichton

https://docs.google.com/spreadsheet/ccc?key=0An9tLRVf1SSfdE9jX1Q2QkhiUGVwTnh5YTJnMHVUYXc&usp=sharing#gid=6
auto merge of #12944 : mcpherrinm/rust/master, r=alexcrichton
auto merge of #12945 : cadencemarseille/rust/vec_ng-as_mut_ptr, r=alexcrichton
rustc: disallow trailing parentheses for nullary enum variants

Fixes #12560