Merge pull request #40 from xiehuc/master

ref-man support <count> K to choose man page
add norelativenumber option
Merge pull request #41 from cohama/no-relativenumber

add norelativenumber option
-page option for source man to optional
Merge pull request #42 from todesking/man-page-option-to-optional

-page option for source 'man' to optional
add cpp to ref-man

Signed-off-by: xiehuc <xiehuc@gmail.com>