* Migrate eventListenerFactory to extension function
* Inline platformTrustManager
* Migrate delimiterOffset to extension functions
Also overhaul these and other string-manipulating functions to have default arguments for start/end indices.
* Migrate hostHeader and toHeaders to extension functions
* Migrate sameConnection to extension function
* Migrate bomAwareCharset to extension function
* Migrate verifyAsIpAddress to extension function
* Migrate indexOfControlOrNonAscii to extension function
* Migrate skip(Leading/Trailing)AsciiWhitespace and trimSubstring to extension functions
* Migrate toHeaderBlock to extension function
