Add support for the STM32152 and STM32162 Medium+ density parts (plus miscellaneous other improvements to the original STM32151 logic).  From Jussi Kivilinna and Sami Pelkonen

The Nucleo-F401RE has no on-board cystal and, hence, must use the on-chip HSI oscillator for the PLL include clock

SAM4S Xplained Pro: Clean-up of LED usage and also some integration of new timer features.  From Bob Doiron

The alternate console device CONFIG_NSH_CONDEV must not be defined unconditionally.  This causes errors when using Telnet sessions.  This was solved by adding CONFIG_NSH_ALTCONDEV: CONFIG_NSH_ALTCONDEV enables or disables the feature then, if enabled, CONFIG_NSH_CONDEV provides the alternative console device name

If the CPU load measurements are being driven by an external clock, then the prototype for sched_process_cpuload() must be available in include/nuttx/arch.h

Updated changelogs and release notes in preparation for the 7.2 release.  Still need to do a little more before the release

STM32:  More places where up_prioritize_irq is called when CONFIG_ARCH_IRQPRIO is not defined.  Sourceforge ticket #26

Sourceforge ticket #26: STM32 up_prioritize_irq should not be called if CONFIG_ARCH_IRQPRIO is not defined

Fix Bob's name in as many places as possible; Make sure that Bob is an author in as many files as I can think of (might be missing a few)

Various SAM4S related fixes, mostely related to the timer driver driver and the SAM4S timer/counter.  All from Bob Doisin

LPC17xx:  Prioritized interrupts are not supported (although hooks are present to prioritize interrupts).  Make LPC17 Ethernet default priority to be the system default, not the highest.  If the unsupported feature is enabled, then at least it should do no harm

LPC17xx, TIVA, and Kinetis interrupt initialization:  use the NVIC ICTR register to determine how many interrupt lines/registers are supported by the MCU