Arduino 1.6.6

What's new in this version:

IDE:
- Switched to Java 8, which is now both bundled and needed for compiling the IDE
- Added link to unofficial boards support list in preferences
- Limit of possible new sketches in a day raised to 676. Thanks @Chris--A
- Windows: fixed a bug when running username had non ASCII chars
- Lots of fixes
- ArduinoISP examples moved under 11.ArduinoISP folder
- MacOSX: binary is now able to tell the IDE its current working directory. Eases life to those using the IDE from the CLI
- CLI: if specified board doesn't exist, fail instead of using a default one
- Windows: IDE stores its stuff under %LOCALAPPDATA% instead of %APPDATA% (which was a roaming folder). %APPDATA% content is automatically migrated to new location
- Added 74880 baud rate to serial monitor. Thanks @Chris--A
- When changing tab, file name is shown in window title
- IDE groups compiled files into "libraries", "core" and "sketch" folders
- Added Serial Plotter. Thanks @henningpohl
- Editor: triple click selects whole line
- Windows: IDE startup feels faster
- Examples of libraries with a .development flag file in their root folder won't get marked as read-only. See #2619
- Update notifications: when updates are available from either Library or Boards Managers, a popup will be shown
- Introducing arduino-builder, a command line tool that properly calls gcc. Fixes lots of issues about buggy preprocessing.
- Each open sketch gets built in its own folder, allowing the IDE to recycle previous compilations and being much faster
- "Go to line": CTRL+L or Edit > Go to line... will open a dialog where you can type the line number where you want the editor to jump to
- Added boards.local.txt support: like platform.local.txt, allows to enrich a boards.txt definition without modifying the original file. Thanks @Wackerbarth
- Library to library dependencies: when your sketch imports a library, and that library uses another, the IDE will find out without you having to add a useless #include to your sketch
- Allow per-platform keywords.txt. Thanks @PaulStoffregen
- Allow spaces in IDE install path on Linux. Thanks @matthijskooijman
- Fixed a lot of documentation. Thanks to @per1234 @q2dg
- Fixed parsing for SystemProfiler when scanning for available serial ports on Macosx El Capitan

Libraries:
- Bridge: YunClient.connected() returns true if there are bytes available for read. Thanks @RobAtticus
- Bridge: YunClient.stop() now empties all buffers. Thanks @RobAtticus
- Ethernet: Added missing keywords. Thanks @per1234
- Ethernet: Fixed DNSClient.inet_aton() function. Thanks @jhorck
- Ethernet: Expose optional DHCP timout parameters to Ethernet:begin(). Thanks @chaveiro
- Wire: Implemented Wire.end().
- Wire: Fixed bug with repeated START for AVR. Thanks Nate Williams
- Wire: Resolved timing issues on AVR. See #2173 #1477.
- Wire: Fixed bug in repeated start in slave mode on SAM. See #3908
- SD: Change "char *" to "const char *" on methods accepting a string as a parameter. Thanks @Ivan-Perez
- Scheduler: Added support for cortex-M0. Thanks @PeterVH

Core:
- Added new PluggableUSB and HID support. This change introduces a more powerful API for
- libraries that wants use advanced features of USB-Device.
- Thanks to @obra @NicoHood @matthijskooijman @nospam2000 @weizenspreu
- AVR: fixed wrong turnOffPWM() for TIMER0B. Thanks @gonzoveliki
- AVR: added support for AtmegaXXu2. Thanks @NicoHood
- AVR: a bunch of USB Core bug fix. Thanks @NicoHood
- AVR: Expose serial setting from USB-CDC serial port. Thanks @matthijskooijman
- ArduinoISP is now compatible with every architecture (not only AVR) and is much more stable. Thanks @PeterVH
- Print not aborting on write() failure. Thanks @stickbreaker
- AVR: Faster interrupts patch. Thanks @xxxajk
- AVR: Fixed pulseInLong wrong measurements.
- AVR: Removed a bunch of compiler warnings. Thanks @NicoHood
- Improved variants files for Boards Gemma and Ethernet