m_realloc: Account only allocation size difference in total_bytes_allocated.
Add new alloc metric: current_bytes_allocated.

Unlike total_bytes_allocated, this tracks m_free()'s too.
Add new alloc metric: peak_bytes_allocated.

This is just max value of current_bytes_allocated seen.
Make it possible to turn off collecting memory stats (MICROPY_MEM_STATS).
Rename default config file to mpconfig.h, and port's to mpconfigport.h.

mpconfig.h will automatically pull mpconfigport.h.
Merge pull request #49 from redteam316/svg

Added SVG vector logo.
Merge pull request #41 from pfalcon/more-mem-stats

Collect more memory statistics
unix-cpy: Fix mpconfig to work with new scheme.
Worked on list.pop:
* Fixes issue #51
* Adds a specific error message for when you try to pop an empty list.
* Releases some memory if the list has shurnk a lot.
Merge remote-tracking branch 'upstream/master'
renamed some tests to have better names.
Added list.clear. Fixes issue #53.
Implemented list.copy. Fixes issue #54.
Move INT_FMT, etc. declaration into global mpconfig.h .

This in particular makes it available for stm port.
Merge pull request #56 from pfalcon/int_fmt-global

Move INT_FMT, etc. declaration into global mpconfig.h .
Merge pull request #52 from chipaca/master

Tweaks to list.pop.
Add basic implementation of slice object.

So far, only start and stop integer indexes are supported. Step is
not supported, as well as objects of arbitrary types.
Implement BUILD_SLICE opcode (2-arg version).
str: Initial implementation of string slicing.

Only step=1 and non-negative indexes are supported so far.
Enable slice support in config.