Add common linker script for MPIDE version 0023-*-20130817-test.
Include assembly vector table in chipKIT build.

* Added build step for assembly files in CORE
* Removed duplicate flags from AS build step
Update `HISTORY.md` about ChipKIT 2013 support
Auto detect and include libraries specified in `USER_LIB_PATH`

Fix #135
Use MAKEFILE_LIST to get the name of the make file

This way we don't assume the make file is 'Makefile' and it will
work even if it is named as 'makefile' or 'makefile-uno'

Fix #130
Adjust path to avrdude/avrdude.conf for MPIDE in Linux.
Merge pull request #137 from peplin/chipkit-avrdude-mac

Adjust path to avrdude/avrdude.conf for MPIDE in Linux.
Don't append port details to avrdude for usbtiny

Fix 138
Add option to set fuses without burning a bootloader

When using ICSP programmers e.g. usbasp, you can burn sketches directly
to the chip without having to burn a bootloader, however you do need to
set fuses e.g. if you're changing speed/BOD.

Updated help text to include "make set_fuses" and also changed
"make burn_bootloader" help text which wasn't entirely accurate.

Fix #141
Merge pull request #140 from PPvG/master

Don't append port details to avrdude for usbtiny
Update changelog about `usbtiny` fix
User-defined or calculated bootloader parent directory, allows for
relative paths as defined in boards.txt  e.g. "atmega"

Also added [USER] to ARDUINO_SKETCHBOOK detection

Fixes #126
Merge pull request #142 from sej7278/master

User-defined or calculated bootloader parent directory
Update changelog about the last pull request #142
Add `CONTRIBUTING.md` explaining how to contribute to this project
Allow target specific optimization levels/debug flags

Changing the optimization level from -Os to something else breaks the
SoftwareSerial library. This patch allow optimization flags to be set on a
per target basis.
Merge pull request #143 from mahoy/master

Allow target specific optimization levels/debug flags
Use `ARDUINO_HEADER` variable instead of hardcoded file names

Fix #131
Add information about license in `README.md`

Fix #128
Bump up version number to v1.1.0 for release