* OTA for W800
Removed unnecessary (and wasting resources) fetching of "index?status=1" on pages not using "state" div
Added simple "internal OTA" (just POST-ing a file)
Basic tests done - try avoiding other TCP connections to save memory
Somtimes there are memory related messages in log like "Thread create HTTP Client - errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY".
OTA working in most cases, somtimes device crashes during update.
Device will immediatly reboot after OTA completion, even printfs after writing last bytes was not visible in console.
* Add some more warnings
Make file selector accepting images on extension for platform
For Beken: Check magic "RBL" and future Platform name in header
* Changed way to verify firmware files: must match OBK file structure for the platform
As suggested by @NonPIayerCharacter added "NO_PLATFORM_OTA" in obk_config.h
For platforms w/o OTA the page will be only showing a hint.
* Fix page for non OTA devices
* streamlined tests
moved platform dependent #define for OTA extension to obk_config.h
* Optimized JS code
Only show hint for ".rbl" file on Beken platforms
Added a #define OBK_OTA_NAME_EXTENSION, actually only for LN882H
(here UART and OTA file are identicaly except an "_OTA" in the file name).
Otherwise the UART file would also match the template
(this file would not be flashed because of additional checks, but if we can prevent this ...)
* Add possibility to call a shell script to make changes to sdk just before building the app
* Changes to Makefile
* Changed pre_build.sh to only contain some comments how to use it
* Speeding up consecutive builds
Update Makefile for W800:
Download toolchain only once
- after downloading and extracting create a file
- check for presence of this file before downloading and extracting again
* fix linebreak
