pass test in fedora 20

feature in fedora:
   only enable/disable and crashkernel configuration
   only support crashkernl="numberM" syntax
pass tui test in fedora20

     feature: fedora support enable/disable and crashkerle=xxxM syntax
              redhat also support auto
     defect: both fedora and redhat can't restrict the range of
             crashkernel. This may cause system reserve too much or too
             little memory.
Add reserve memory restriction for tui

If the reserved memory out of range, changing to default. For redhat
is auto, for fedora is the minimun memory needed by kdump.