add mupdf example: outline
add outline API
add mupdf-qt example: test_outline
Merge branch 'outline' into dev
replace tab with spaces
refactor code
modify .travis.yml
add TextBox
add mupdf-qt example: test_text
modify cmake project files of mupdf-qt examples
remove bad comment
fix memory leak errors
fix memory error with Page and Outline
use valgrind to check memory leaks
modify .gitignore
refactor code related to Page
refactor code related to Outline
refactor code related to Document
modify Page::size()
remove Page::setTransform()