Instead of calling lfs.mkdir() to create "./history" and "./screenshots"
at runtime it is easier to create them at package build time.
I hesitated whether to add "./clipboard" to this list but decided
against it as we can perhaps change current directory and then
all the code manipulating clipboard would break, so I left it as is.
Latest changes for history support move configuration files into
history directory to keep them as timestamp for last read. This code
also adds reading of old configuration files (but does not remove them)
- long lines (filenames in 'Document Info') are now splitted in more
human-readable way (by spaces, dots, slashes or some other characters
- see screenshot)
- the selection of fonts in filemanager (key 'F' or 'Aa') looks now more
user-friendly
- fixed too long strings in most menues (TOC, Bookmarks, Fonts...) and
in the popup with the reading progress (called by key 'Menu')
- the position inside the cr-documents (epub, mobi...) now remain nearly
the same after rescaling the document (i.e. changing the font face,
size, boldface and interline distance)
- when you open TOC-menu or Fonts Menu, it highlights the current item
(i.e. current chapter and current fontface).
- i've a bit changed the way to read the battery level values, it might
now work even without Amazon Kindle framework.
