Arduino 1.5.x - support new library layout and plaform specific system libs

- Add support for 1.5.x library layout.
  (https://github.com/arduino/Arduino/wiki/Arduino-IDE-1.5:-Library-specification)

- Allow using Arduino 1.5.x platform specific system libraries.
  Arduino 1.5.x has additional directories for platform (vendor/architecture)
  specific libraries - look there when searching for libraries.
Replaced double quotes with singles when passing arguments to
avr-objcopy. Windows doesn't seem to like double quotes.

Fixes issue #272, thanks @vogt31337
Merge pull request #274 from sej7278/master

Replaced double quotes with singles.

Fix #272
Add changelog entry for #275 and #276
remove unwanted TABs
do not print default (empty) ARDUINO_PLATFORM_LIB_PATH value for arduino 1.0.x
support for Teensy 3.x via Teensy.mk
minor tweaks to Teensy.mk
Merge pull request #277 from lukasz-e/arduino-1.5.x-libs

Arduino 1.5.x libs - handle new library layout (issue #275) and hardware/vendor specific libs (issue #276)
Merge branch 'master' into up-auto
Teensy.mk: default to arm-none-eabi-xxx for executable names. Tweak the upload/reset stuff a little more. Add COPYRIGHT block.
Added Teensy to HISTORY.md
Added BlinkTeensy example which uses the Teensy.mk file.
Make BlinkTeensy a NON_TESTABLE_EXAMPLES
move ARDUINO_DIR auto-detection into Common.mk. This allows Teensy.mk to use auto-detected location.
Teensy.mk: simplify setting of MCU and MCU_FLAG_NAME
put ARDUINO_DIR block after Travis-CI block else travis will fail.
added info about Teensy to README.md
Add's "avrispmkii" to the list of ISP's that don't have a port,
defaults to reading communication_type from avrdude.conf, which
is "usb" usually, rather than setting the -P flag which is the
user override.
Merge pull request #281 from stepcut/teensy.mk

Add support for Teensyduino 3.x