add operating definitions of UART0 to UART5
support UART0 to UART5 straightly
add RT_USING_UARTx and set console via uart0
add CM_PER_UARTx_CLKCTRL
friendly for uart count under 6
Add INIT_FS_EXPORT for RAM file system
[scons] Add the library to the group when used buildlib building
[DFS] Add ramfs initialization in components initialization procedure
add JavaScript Interpreter
Merge pull request #227 from RTsien/master

Add supports for UART0 to UART5 of beaglebone(black)
Merge pull request #240 from geniusgogo/JS

add JavaScript Interpreter
Update SConscript
[JS] fix the include path issue
Use DeviceDriver ringbuffer.
Add hardware flow support.
Use new struct serial_ringbuffer.
Fix uart device driver for gpio remap and hardware flow control.
Add uart4 and uart5 device driver.
Merge pull request #241 from bright-pan/master

Add RTS/CTS option in the serial framework.
Fix rt_serial_control() bug for customized command and indent the code
Merge pull request #242 from bright-pan/master

Fix rt_serial_control() bug for customized command and indent the code
Revert "Merge pull request #241 from bright-pan/master"

This reverts commit 5aeedc4f3a3c3fcfffb0cd4a474f5faa75053839, reversing
changes made to 3d80e414ff6c03ff04fecb914e7aa9b3fb535e03.

This merge breaks every uart driver in all BSPs. @bright-pan , is there
any way to get this done without breaking existing code?
Merge pull request #243 from grissiom/serial-rollback

Revert "Merge pull request #241 from bright-pan/master"