refactor uCShell.c and move anything that can be user setting to config file

[EdwinFairchild]

uCShell/uCShell.h

Line 90 in 49d04bd

#define MAX_NUM_OF_COMMANDS 10

uCShell/uCShell.h

Line 92 in 49d04bd

#define MESSAGE_MAX 50

uCShell/uCShell.c

Line 130 in 49d04bd

char *tokens_found[10] = {NULL};

should not use a magic number, this values 10 should be MAX_NUMBER_OF_ARGUMENTS