switch view_mode to scroll for search results

This will position page on first search result.
Merge pull request #780 from dpavlin/fix_scroll_pos

switch view_mode to scroll for search results
Factored out C/C++ API to submodule koreader-base
some adaptions to factored out C/C++ API
generate git-rev on package build
updated submodule koreader-base
updated koreader-base submodule to its new URI
Merge pull request #822 from houqp/make-fix

generate git-rev on package build
updated kindlepdfviewer repo location
Merge pull request #823 from hwhw/master

update repository location in a few places
add bootstrapemu target in Makefile & update README
update koreader-base
update gitignore
Merge pull request #824 from houqp/master

add bootstrap emu for old code base
adaptions to koreader-base framework

This is not yet perfect, rendering text doesn't seem to "add" the values
correctly.
Merge pull request #825 from hwhw/master

Adaptions for new koreader-base framework