Change DAPLink version to 251

Change DAPLink version to 250

Change DAPLink version to 249

Change DAPLink version to 248

Bump version to 0246

Bump the version from 0245 to 0246.

Bump version to 0245

Bump the version from 0244 to 0245.

Disable interrupts when performing flash ops

Update the atsam3u and kinetis flash drivers so they disable
interrupts when erasing or programming flash. This prevents
a crash from occurring if an interrupt occurs during flashing
when the flash cannot be read.

This also fixes a watchdog reset on K20 interfaces which occurs when
an interrupt interrupts the watchdog unlock sequence in the flash
"Init" function.  The addition of this critical section prevents the
watchdog operation from being interrupted.

Base IAP device info on memory map

Ensure a device's memory map is kept in sync with its device info by
using memory map defines and asserting on an unintended change.

Remove features so bootloader fits in 20K

Remove unnecessary features so the bootloader can fit within 20k.

This patch makes the following changes:
* Remove hex file parsing
* Bypass flash decoder layer since this is not used by the bootloader
* Remove flash intercept code in IAP flash layer since this is not used by the bootloader
* Remove files MBED.HTM, ASSERT.TXT, NEED_BL.TXT
* Remove entries from details.txt
* Remove most action commands
* Reduce size of MBR init data
* Remove all error messages in FAIL.TXT except for success and failure
* Remove read/set assert in config ram
* Remove unused vector table entries to free up space

Notes about the tool version used to build a 20K bootloader image:

IDE-Version:
µVision V5.23.0.0
Copyright (C) 2017 ARM Ltd and ARM Germany GmbH. All rights reserved.

Tool Version Numbers:
Toolchain:        MDK-ARM Professional  Version: 5.23
Toolchain Path:    C:\Keil_v5\ARM\ARMCC\Bin
C Compiler:         Armcc.exe        V5.06 (build 20)
Assembler:          Armasm.exe       V5.06 (build 20)
Linker/Locator:     ArmLink.exe      V5.06 (build 20)
Library Manager:    ArmAr.exe        V5.06 (build 20)
Hex Converter:      FromElf.exe      V5.06 (build 20)
CPU DLL:            SARMCM3.DLL      V5.23
Dialog DLL:         DARMCM1.DLL      V1.17.0.0
Target DLL:         CMSIS_AGDI.dll   V1.27.5.0
Dialog DLL:         TARMCM1.DLL      V1.12.0.0

Note - when building with this version the complier to use must be
explicitly chosen to be V5.06 (build 20) in the "Target" tab of
project options. Furthermore, after chaning this setting, the
optimization level must be re-cofigured to "Level 2 (-O2)" in the
C/C++ tab.