A lot of manga comes as .zip, and not .cbz (for all intents and purposes, it
is the same thing, just the extension is different). This allows the user to
choose the reader to open her zip files - PDFReader or CREReader, in the same
way she can choose to use PDFReader or PDFReflow for pdf files. I also moved
the list of supported extensions to defaults.lua.
when select a reader to open a document the readerchooser dialog is
overlayed with opening file notification window. The overlayed three
windows(file chooser, reader chooser and notification window) will make
users feel unconfortable easpecially when opening in koptreader which
usually freezes the screen for several seconds.
With this patch the reader chooser dialog is closed before the opening
file noticifation is shown up.
When there are reader preferences table but preference for the file type
of which the file is to be opened is not available, reader chooser
should show up.
I changed `last_reader` and `default_reader` to `reader_association` and
`reader_preferences` respectively for clearness.
Users can still use default reader for specific type. The "Remember
this file" option will add exception to the predefined reader
preference. And exception for a document can be made with the "Alt+C"
command after opening the doc. This patch fixed the bug reported on
issue #480 by @dracodoc.
