Save/restore float registers on task switch
Add screen shots
Write how to create Haribote application
Add more screen shots
Update README
Add original license text
Fix Makefile to do optimize
Overwrite linker script setting using `defsym` command line option
Fix comment
Split OS main loop function
Make Mandel application not to waste CPU power
Handle cursor key
Update README.md
Draw shaded box
Add `delete` API and `del` command

This is just done on memory, and does not write back to a floppy disk.
Read RTC and Add `now` command to print current time
Move FILEHANDLE definition from mtask.h to file.h
Change `fopen` not to copy file data
Change `tview` to handle cursor key
Change `file_loadfile` to use `file_read`