Log Message:
Update to 1.20

Changelog:
* 1.19:
        + fixed the table of contents display for most non-Latin
        character set documents (provided you get a Unicode
        build).
        + fixed linking issue for wxWidgets 2.9 (the AUI libraries
        were not being pulled in).
        + fixed a bunch of minor bugs.
* 1.20:
        + fixed a nasty bug that crashed the application with some
        CHM files.
        + fixed strict-aliasing compile-time warning.
        + fixed a few signed/unsigned comparison warnings.