Corrected pinmaps for stm32f40xxx processor
Merge https://github.com/PX4/NuttX
stm32_i2c: ensure that unexpected ISR can't overwrite stale data

if we get an ISR leftover from a previous read transfer it could use
stale values for priv->dcnt and priv->ptr to overwrite stack that is
no longer in scope. This resets dcnt and ptr on each new
stm32_i2c_process() call to ensure that any unexpected data bytes are
discarded
Fixed include guard in cstdio. Broken include guard was preventing cstdio to compile if cctype was included first (and vice versa); as a result, the code that needed both cctype and cstdio was failing to compile.
Merge pull request #14 from pavel-kirienko/cstdio_guard_fix

Fixed include guard in cstdio
Declared log2l() in ARM math.h
Merge pull request #16 from pavel-kirienko/arm_math_log2l

Declared log2l() in ARM math.h
Merge pull request #8 from sarthakkaingade/master

Corrected pinmaps for stm32f40xxx processor
Merged master into merge test