apps/examples/helloxx entry point name was mangled when built as an NSH builtin; plus some README updates

configs/hymini-stm32v converted nsh and nsh2 configs to use kconfig-frontends tools; Also converted to use the common SSD1289 driver

Default NxWidgets and NxWM priorities should be 100 not 50 to be consistent with other default priorities

configs/mikroe-stm32f4:  Add new configurations plus support for the MIO283QT2 display from Ken Pettit

Rearchitecting of some MTD, partition, SMART interfaces, and FLASH drivers to:  Better use the byte write capbility when available and to use smaller erase sectors for the erase sector size when available).

Various Kconfig files still have references to CONFIG_ variables.  Some in harmless comments, some in config definionts which is not harmless.  All removed