Tries to find one of the predefined ContactField for the scheme, which can be
either the scheme itself, like "icq:", or a scheme with the value, like "icq:1234".
The out_scheme_len can be used to return how many letters from the beginning of the scheme can be skipped to
get to the actual value. Returns value e_contact_field_last means no matching
ContactField was found for the scheme. The
e_contact_impp is never returned, then the scheme can be a valid scheme, only the
ContactField does not have a mapping for it.
| scheme |
a URI scheme as "icq:", but can be with a value too |
| out_scheme_len |
optional place where to store how many letters the scheme has |
|
an ContactField corresponding to the |