Replaces arduino#4280, only checks for the bootloader once

Tested with Hoodloader2, should work with every LUFA-derived bootloader released after 2014 (.apitable_signatures section must be placed at end of the flash)

BootloaderAPITable.S :

.global BootloaderAPI_Signatures
BootloaderAPI_Signatures:

    .long BOOT_START_ADDR ; Start address of the bootloader
    .word 0xDF00 ; Signature for the CDC class bootloader
    .word 0xDCFB ; Signature for a LUFA class bootloader

makefile:

BOOT_API_LD_FLAGS    += $(call BOOT_SECTION_LD_FLAG, .apitable_signatures,  BootloaderAPI_Signatures,  8)

Disable Compile/Run buttons as they get press, and reenable only on function exit.
The launched upload process has now a 2minutes timeout before being terminated forcefully.
10 second after pressing "Upload" the button comes pressable again, but this time the previous upload command gets killed explicitely

This commit introduces the concept of stateful board list (vs. original stateless) and board serial number.

The board is now an "entity" composed by the triplet port/vid/pid. These informations come from libListSerial "light" function. When the board list changes, it triggers a request for the additional infos to libListSerial. These information contains the serial number of the boards.

These brings a lighter and faster scanning process. Some logic has been introduced to handle a board with the S/N only exposed in the bootloader (like 32u4).
In this case the disappearing port acquires the bootloader's S/N

A menu (under Ports menu) shows the currently connected port info and can be used for bugreporting

The current method of reporting upload errors is based on an exoteric combination of exceptions which makes return error code useless
The Uploader.java message() implementation is too avrdude-dependant to allow easy portability since the upload tools are becoming a lot and very different

With this commit we try to avoid exceptions and only use the external uploader's exit code to decide the status bar message.
The message can be:
- the last line containing "error" string (any case) or
- the usual avrdude message parsing (to keep compatibility with translations)

Needs testing with all platform and all supported upload tools

by doing so, runtime variable are resolved by using the board specific tools

real life example:
- Intel i585 defines sketchUploader (version 1.6.2)
- Intel arc32 defines sketchUploader (version 1.6.4)
- runtime.tools.sketchUploader.path gets the value of the last one processed

with this PR

runtime.tools.sketchUploader.path.Intel.arc32 and runtime.tools.sketchUploader.path.Intel.i586 get created

when resolving {runtime.tools.sketchUploader}, the routine searches for a key runtime.tools.sketchUploader.Vendor.Architecture

If found, the value is obtained by {runtime.tools.sketchUploader.Vendor.Architecture}.getKey(), which always contains the required value.
If no value is found, the old methos is applied

OS X 10.11 seems to be slower, increasing timeout to 5s on all
platforms to keep things simple.

…source busy" errors on open

This reverts commit a86176d.

If a sketch contains a link to http://librarymanager/${dropdown}#${filter} or http://boardmanager/${dropdown}#${filter} (for example http://librarymanager/All#OneWire) Library or Board manager will be opened applying the secified filters

fixes arduino#4701

from listSerialsj library 1.0.8 the serial polling is executed using the listComPorts method (which is much more cpu intensive than the previous one) to avoid bug arduino#4700. The 3 second poll rate is needed to avoid cpu hogging