String size refactor take 2 next wave

patched the following

- ext/zlib
- ext/iconv
- ext/mbstring
- ext/intl

Fixed internal ext/pcre functions to work with zend_str_size and consequently the usage in SPL.Some other small fixes are there for CLI, datetime, etc. Regarding PCRE it uses int, so we should thing about submitting a patch or at least filing a bug to PCRE itself to fix that.

The ext/intl should be reviewed though as ICU works with int32_t for string sizes. Also it contains things like the stollen ascii substr implementation (from ext/standard). As of now it works, may be it can wait until we integrate int64.