Merge pull request #240 from houqp/houqp-master

add hidden file toggle for file manager
Update documentation

Since the build system has changed after modularization. Also,
point out that the project now supports Kobo devices too.
Merge pull request #250 from thotypous/master

Update documentation
fix widget out-of-bound in bookmark and toc menus
The original menu layout needs manual dimension calculations
such as  white padding for displaying page information in
footer as the title, all item contents and footer are stacked
in one VerticalGroup. Out-of-bound error(koreader/koreader-base#43)
will occur in some corner cases if we missed something in
the calculation. The patch sent in this PR invented a new
layout for menu widget in which no manual calculation is needed
for displaying the footer. And the footer will be placed well
inside the menu frame.

   +--------------+
   | +----------+ |
   | |+--------+| |
   | || Header || |
   | |+--------+| |
   | |+--------+| |
   | ||  Item  || |
   | ||  Item  || |
   | |+--------+| |
   | |(Vertical | |
   | |  Group)  | |
   | +----------+ |
   |    Footer    |
   |(OverlapGroup)|
   +--------------+
split string with delimiters captured
Merge pull request #255 from chrox/dict_unicode

split string with delimiters captured
Merge pull request #254 from chrox/menu_layout

fix widget out-of-bound in bookmark and toc menus
Solve bug #210.
Merge pull request #258 from giorgio130/master

Solve bug #210.
update koreader-base
Merge pull request #259 from chrox/master

update koreader-base
update k2pdfopt to version 2.00
add a UTF8 character iterator

this speeds up font rendering since LuaJIT doesn't have to use
the interpreter for string.gsub(), which was used before
fixed bugs in implementation of utf8Chars()
Merge pull request #261 from hwhw/master

add a UTF8 character iterator
Merge pull request #260 from chrox/master

update k2pdfopt to version 2.00