* fix(font): Remove the unnecessary and duplicated inclusion
and correct some wrong comment too
* fix(font): Handle the out of memory gracefully in decompression case
and remove the check of gdsc since it is impossible to become null
* fix(font): Use the correct type to avoid the cast and shift
* fix(font): Change the bit field width to occupy the whole byte
* fix(font): Correct _LV_STR_SYMBOL_ generation command
and add _LV_STR_SYMBOL_BULLET to the list
* fix(font): lv_font_load shouldn't call lv_fs_close if lv_fs_open fail
* fix(font): read_bits should return 0 not -1 in error case
to avoid read_bits_signed waste time to extend the sign bit
* fix(font): Correct the return type of read_bits to unsgined int
and extend the sign bit more efficient and correct
* fix(font): Sync LV_FONT_FMT_TXT_CMAP_ value to binary font spec
and then remove the hard code value from source code:
https://github.com/lvgl/lv_font_conv/blame/master/doc/font_spec.md#L96
remove zero fields statement too since font_dsc->cmaps already zero at line 334.
* fix(font): Improve the performance by reading cmap table by once
* fix(font): Improve the loading performance if the header is multipled by 8bits
* fix(font): Read loca table in batch if the size is 32bits
* fix(font): Load the underline related attributes
spec here:
https://github.com/lvgl/lv_font_conv/blame/master/doc/font_spec.md#L55-L56
* fix(task): Remove the unnecessary cast and init
and correct the comment too
* fix(task): Implement lv_task_create directly
to avoid lv_task_set_prio which is a time consuming operation.
* fix(task): Exclude the return value computing from the idle time
and change handler_start and time_till_next to local variables
* fix(task): Remove zero task_deleted and task_created in lv_task_exec
since the loop in lv_task_handler already do the same thing
