Add new typedef to deal with global variable
Replace all PWM Input Capture Value to the new global struct

I will change all global variable to this type step by step.
Unify some naming and declaration
Unify some naming and declaration
Replace all global r/c var to new style structure
Add one safety switch, it could let motor be minimum speed

WARNING: This code still have some type casting bug, need to fix it
Change PWM3~5 counter variable to uint32_t
Because TIM2 CCR is 32bit register, it is more reasonalbe
to use uint32_t
Handl more condition and fix some error
Change param init to be 0 and add prefix to protect gloabal variable
Add all my headers to be dependencies

I add all of my header to be the dependencies of EXECUTABLE.
This action ensure when I change the header file(.h), Makefile
will also rebuild my souce code.
Fix compliation warning
Add a stringization macro for debugging
Use macro to define some constant
Handle NO RC signal timeout situation
TODO: Handle the situation: R/C transmitter OFF, but still get CCR value from PWM input
This method only can detect zero PWM input capture
value. Sometimes, the RC receiver keep the last value which
get from RC transmitter. That means MCU still "gets PWM input
capture value". We need to deal with this situation in future.
Merge pull request #16 from poemking/master
Rewrite test function and fix compliation warnings
Use float to instead of uint16_t in global variable
Replace classic gdb to gdbtui
Delete some unused code, I will not use these anymore
Enable safety switch off