Rust: Fix parsing of function pointer struct fields.

Previously, skipUntil was confused by the -> token.
Rust: Fix parsing of attributes in structs/enums.

Previously, things like:

struct Foo
{
    #[bar]
    baz: int
}

or

struct Foo
{
    #![bar]
    baz: int
}

would horribly confuse the parser and prevent proper parsing of the rest of the
file.
Rust: Allow [] delimeters for macros.

New Rust syntax.
Rust: Update ctags tests.

Also, make them compile again with the Rust compiler.
Rust: Update keywords
Rust: Skip 'pub' keyword in front of struct fields.
Rust: Add some more syntax examples to the CTags test file.

Also, made it compile again.
Rust: Add a test for leading 'priv'.
Merge branch 'SiegeLord/rust_updates'