Make the low available memory message a warning

Write the low available memory message to err rather than out so that it
appears more like a warning and is more noticeable.
Wire library, move hard references IRQn to defines in variant.h
Minor changes to Communication Examples

Added a note to the included Processing sketches about replacing
println(Serial.list()) with Serial.printArray() if using Processing 2.1
or later
Update readme.txt
Update and rename readme.txt to README.mkdn
Rename README.mkdn to README.md
Updated Listfiles SD example

Changed SS pin to 4 for consistency with other examples
Merge pull request #1836 from KonradIT/master

Use markdown lang in the readme.
Merge remote-tracking branch 'arduino/master' into ide-1.5.x
Fixed typo in test
Merge remote-tracking branch 'arduino/ide-1.5.x' into ide-1.5.x
WiFi Shield examples: added the firmware version check
Added command line option --verbose-build and --verbose-upload
Added license for avr/HardwareSerial.

See #1847
Added license for Client, IPAddressm and Server

See #1847
Added license for Arduino.h, binary.h and main.cpp

See #1847
If 2 libs have same .h file, use the lib with same dir name
Merge pull request #1853 from PaulStoffregen/master

If 2 libs have same .h file, use the lib with same dir name
Merge remote-tracking branch 'arduino/master' into ide-1.5.x

Conflicts:
	app/src/processing/app/Base.java
Fixed issue #1478, #1599, #1709, motors being opposite, updated turning algorithm