Added utility ECollator to libedataserver.

Added utility ECollator to libedataserver.

The ECollator API wraps up the required ICU APIs into something more
convenient for usage in EDS. The provided features allow for rich
locale sensitive sorting as well as knowledge of the user's native
alphabet.

Some auxilary objects are needed to access features in ICU which are
available only in C++:

    EAlphabetIndex

    A private accessory used internally by ECollator to implement AlphabeticIndex
    features. This is in a separate file since we need to use C++ APIs to use
    the AlphabeticIndex, so we compile it into a separate archive to be statically
    linked in with libedataserver.la.

    ETransliterator

    Added this glue to call icu::Transliterator C++ APIs on behalf of ECollator.