* [image file view] added a zoomer(enable users to zoom in/out the image)
* [image file view] added 'rotate'(rotate the image in counter-clockwise direction and save it)
* [image file view] fixup
* [image file view] keep the 'prev/next' icons displayed on top of the image which is zoomed in
* [image file view] improved the display of the 'image saved' tip
* [image file view] don't offer 'zoom in/out' & 'rotate' for images with errors
* [image file view] don't offer 'rotate' for PSD & HEIC files
* [image file view] enable HEIC files to be viewed online
* [pdf file view] added 'find' operation icon; redesigned the 'find' bar
* [pdf file view] the 'find' bar: updated the 'find previous/next' buttons; added a 'clear query' function
* [pdf file view] 'print': redesigned the 'Preparing document for printing' dialog
* [pdf file view] the 'find' bar: updated the styles of the border & the 'input'
* [pdf file view] 'preparing document for printing' dialog: updated UI details
* [pdf file view] 'preparing document for printing' dialog: modified the border & the backdrop
* [onlyoffice file view] added a custom toolbar(star/unstar, smart link, details, open parent folder, fold/unfold)
* [onlyoffice file view] added a new 'details' panel for it
* ['notice' popover, 'all notice' dialog] fixup for mobile
* ['Files' page] fixed library icon size for mobile
* ['settings' page] fixup for 'Email notification'
* ['my libs'] fixed 'star/unstar', 'share', 'delete'
* ['deleted repos' dialog] modified column width of the table for mobile
* ['share' dialog] modified 'link details' panel for mobile
* [side panel resizer] removed it for mobile
* [group/department, shared with all] fixed the operation menu for mobile
* ['dir view'] don't offer 'repo history' page for mobile
* ['help'] fixup for page with large images, for mobile
- fixup for http://127.0.0.1:8000/help/drive_client_2.0_for_windows_10/
(in mobile, the content of it overflowed to the right, and was cut off)
* ['file view'] removed 'history' page for mobile
* ['markdown file view'] removed 'history' page for small screen, mobile
* ['dir view'] added a gray layer to close the 'file/folder tree' panel in mobile
* ['dir view'] fixup for the 'path' bar in mobile
* ['dir view', 'shared dir view'] don't display the 'tag list' in root for mobile
* ['file view'] use new icons(svg icons)
* ['file view'] use new icons for 'markdown file view' page
* ['file view'] for 'markdown & other text files': highlight the 'Save' button when it can be saved
* [pdf viewer] use the latest PDFjs(v3.8.162)
* [pdf viewer] redesigned it: added side panel(thumbnail panel) and bottom bar(includes side panel toggle, 'file page manager', and 'zoom manager')
* [pdf file view] added 'print' to the top-right toolbar
* [file view] added 'Details' & 'open via client'
* [file view] adjusted places of operations
* [file view] 'open via client': use a new icon
* [file view] 'open via client': updated the icon
