std::dynamic_lib: start fixing windows implementation

The code compiles and runs under windows now, but I couldn't look up any
symbol from the current executable (dlopen(NULL)), and calling looked
up external function handles doesn't seem to work correctly under windows.
Do not strip leading whitespace when parsing doc comments.

This change prevents the indentation in code blocks inside the /// doc comments
from being eaten. The indentation that is the same across the consecutive doc
comments is removed by the uindent_pass in librustdoc.
std::rt: Reduce the delay on a timer test. Slow
Update doc references to new names for std, extra, and std::libc
std: add Zero impls for &[] and &str.
Reproduce text changes from @brson PR 7176 and fix a typo therein
auto merge of #7198 : huonw/rust/slice-zeros, r=Aatch
Improved std::ascii
- Fixed tests
- Added methods
- Renamed casting methods to be shorter

closes #7150
auto merge of #7195 : brson/rust/timertest, r=bstrie
auto merge of #7174 : SiegeLord/rust/remove_trim, r=brson

This change prevents the indentation in code blocks inside the /// doc comments
from being eaten. The indentation that is the same across the consecutive doc
comments is removed by the uindent_pass in librustdoc.

The bug can be seen, e.g., here: http://static.rust-lang.org/doc/std/iterator.html#example-12

I also altered how the block comments are treated, for consistency. There isn't much testing done on the documentation output (I added a few tests of my own for the modified function), so I don't know if anything relied on the previous behavior. I checked a number of documentation files and observed either no change in output or changes that consistent of the above bug being fixed.
auto merge of #7199 : Kimundi/rust/master, r=bstrie

- Fixed tests
- Added methods
- Renamed casting methods to be shorter
- Added unsafe versions

Closes #7150
Use DIBuilder in debuginfo
Made the while DebugContext mutable, not just created_* hashes
Disabled create_arg
Move "return" basic block after all other function blocks.
Debug loc for local var declarations
Removed extraneous string allocations.
Misc refactoring.
Fixed compile warnings.
Fixed whitespace "errors".
Fixed remaining issues to pass debug-test/* tests.
Made debugger scripts source line insensitive.
Converted vec::map to member.
Made unimplemented debuginfo a note rather than a compiler error.