Auto merge of #381 - michaelsproul:build-doc-fix, r=BurntSushi
Auto merge of #381 - michaelsproul:build-doc-fix, r=BurntSushi

Fix docs for renaming of `RegexBuilder::build`

There were some references to `compile` left over after the rename from `compile` to `build`.

rust-lang-nursery/regex,rust-lang-nursery/regex,rust-lang/regex,rust-lang/regex,rust-lang-nursery/regex,rust-lang/regex,rust-lang/regex,rust-lang/regex,rust-lang-nursery/regex,rust-lang-nursery/regex