* modest_text_utils_get_subject_prefix_len now also deals with   multiple prefixes, such as 'Fwd:Re[34]:Fw:Foo bar" * added parameter checks to some functions
* modest_text_utils_get_subject_prefix_len now also deals with
  multiple prefixes, such as 'Fwd:Re[34]:Fw:Foo bar"
* added parameter checks to some functions

pmo-trunk-r3679

community-ssu/modest,community-ssu/modest,community-ssu/modest,community-ssu/modest