tls: Add support for Elliptic-Curve Diffie-Hellman Ciphers (ECDH)
tls: Added note to docs about OpenSSL requirement for Elliptic Curve Diffie Hellman (ECDH)
db_unixodbc: use odbc_config to find paths for include and libs
db_unixodbc: free local variables in case of errors or no result

- reported by Alex Villacís Lasso
parser: add internal flag FL_BODY_MULTIPART

This will be set if the body has been converted to multipart/mixed
or a new part has been appended to it. This will trigger the core
to check and fix the boundaries of the body.
core: add check_boundaries(). WIP.

This checks and fixes the boundaries of a multipart body if the
FL_BODY_MULTIPART flag is set.
textops: functions to convert, append and remove multipart bodies
textops: add new multipart functions documentation
textops: Refresh README