* Update doc "Where is the current Linux kernel debug image" to make it more clear.
  https://code.google.com/p/kgtp/wiki/HOWTO#Where_is_the_current_Linux_kernel_debug_image
  https://code.google.com/p/kgtp/wiki/HOWTOCN#当前Linux内核调试镜像在哪

* Update doc add section "Load Linux kernel debug image to GDB".
  https://code.google.com/p/kgtp/wiki/HOWTO#Load_Linux_kernel_debug_image_to_GDB
  https://code.google.com/p/kgtp/wiki/HOWTOCN#装载Linux内核调试镜像到GDB