It could fix the problem encountered in
https://groups.google.com/forum/?hl=en#!topic/rt-thread-cnusers/tpqZOMsIp8I

clean code in SConstruct and application.c, disable RTGUI in rtconfig.h
by default.

    1. fix heap management for stm32f0xx(SRAM=8k)
    2. add USART1, USART2 driver for stm32f051R8
    3. fix finsh support for stm32f0x
    4. fix board components initial for stm32f0x and open debug msg
    5. add led driver(pc9) and test thread for stm32f0discovery board
    6. add init thread for stm32f0x do components initial
    7. add rcc initial for stm32f0x in rt_hw_board_init()
    8. add print rcc freq information function

the console output example is:
    SYSCLK_Frequency is 48000000HZ
    PCLK_Frequency is 48000000HZ
    HCLK_Frequency is 48000000HZ
    CECCLK_Frequency is 32786HZ
    ADCCLK_Frequency is 14000000HZ
    USART1CLK_Frequency is 48000000HZ
    I2C1CLK_Frequency is 8000000HZ
    SystemCoreClock is 48000000HZ
    initialize rti_start:0 done

    \ | /
    - RT -     Thread Operating System
    / | \     1.2.0 build Nov 15 2013
    2006 - 2013 Copyright by rt-thread team
    do components intialization.
    initialize rti_board_end:0 done
    initialize rt_hw_led_init:32768 done
    initialize finsh_system_init:0 done
    finsh>>

With new timer algorithm, timer should be initialized during startup. So
add them to the bsps. Use these commands to get which bsp is missing
calling the function:

    % git grep rt_system_timer_init bsp|sed -n 's|bsp/\([^/]*\).*|\1|p' | sort | uniq > have_tm_init
    % ls -1 bsp |sed -n 's|\([^/]*\).*|\1|p' | sort > all_bsp
    % comm -3 all_bsp have_tm_init
    beaglebone
    lpc176x
    lpc178x
    ls1bdev
    mb9bf506r
    stm32f10x
    xplorer4330

We split the history handling form the key handling. So we could handle
the direction key even if the history is disabled. As a "side effect", I
also remove the unnecessary "use_history" bit.

_TIME_T_DEFINED was pre-defined in order to build jffs2 with VC.
While it may cause many side effects.

Now we can get rid off Mingw to create def file. To create def file, one
should run:

    scons --def

in the bsp/simulator.

rename template.vcproj to template_vs2005.vcproj
add template_vs2012.vcxproj
NOTE: the vs2012.py is ugly, just can work.

When CROSS_TOOL or 'RTT_CC' env is setted to 'clang-analyze', it will
use Clang to check the codes.

Simulator get it's way to Travis CI ready.

This could not only make a cleaner SConstruct, but could also benefit
RTGUI building.

The rtgui_system_server_init prototype is wrong. And if we use
RT_USING_COMPONENTS_INIT, there is no need to call
rtgui_system_server_init again.

SDL may use DFS to open files. It should be run after
rt_components_init.

rt_hw_sdl_start should wait untill the rtgui_graphic_set_device is
called int the sdl_loop. Use pthread_cond_wait to achieve this in Linux.