Changes to the USBUART to make it less likely to drop characters at higher baud rates.

USB UART seems to work fine at 115.2Kbps or 230.4Kbps, but starts to drop characters
as the data rate goes higher. This commit changes the usbuart ISR to fill a software
FIFO, and adds a low priority timer interrupt to run deferred processing to drain a
FIFO and send USB CDCACM packets, rather than calling the usb send within the UART
ISR.

Tested on native platform, up to 1.5MBps.
usbuart: Fix build error and clean up whitespace.
Merge remote-tracking branch 'origin/usbuart_highrate'
Update to the newest libopencm3
LPC43XX: Make sure to align target struct to word alignment
LPC43XX: Add mkboot target command; dont make banks bootable by default.

This used to be done transparently in the write step, however that
breaks the 'verify' command. This is also more flexible for cases
where you want to write a flash bank without ever intending it to
be bootable.
LPC43XX: Add reset command to do a system reset (but not the debug).
LPC43XX: Remove type cast for erase function
LPC: Cleanup regs_size (in bytes).

Also use sizeof() to make it clear why we multiple and divide by 4.
LPC43XX: Make the chunk_offset logic more explicit.
LPC43XX: Force target to use internal clock.

Without this, flash write timing might be incorrect.
Fix in checksum calculation condition
Merge pull request #31 from BuFran/pulls/libopencm3_update

Update to the newest libopencm3
Merge pull request #32 from aibara/lpc43xx_updates

Lpc43xx target support updates
Merge pull request #35 from burgrp/upstream

Fix in checksum calculation condition
Add dfu bootloader update application and use absolute delay for stlink

Hello,

appended 3 patches
- adds a dfu-bootloader appliaction
- uses absolute delays when waiting for pull-up delays on the STLINK
(hopefully fixes issue #30)

Updating the dfu-bootloader by additional application is helpfull for the
STLINK, as for flashing the bootloader by SWDb otherwise jumpers need to be
soldered or external SWD is not possible.
Use like:
- dfu-util -s 0x08002000:leave -D dfu_upgrade.bin
- dfu-util -s 0x08000000:leave -D blackmagic_dfu.bin
- Push reset buttom and reconnect to enter new dfu bootloader
- dfu-util -s 0x08002000:leave -D blackmagic.bin
--
Uwe Bonnes                bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------
>From fae5022c304a8866f056ea66660ac7ce3809dcf8 Mon Sep 17 00:00:00 2001
From: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Date: Sun, 20 Oct 2013 15:00:36 +0200
Subject: F1: Prepare to update dfu bootloader via DFU with additional
 application.
Add STM32F03X and STM32F07X handling.
Added support for the LPC1115FBD48/303 (ID determined experimentally)