build: underline package name and version in configure summary

[rbuj]

Test:

$ ./autogen.sh --prefix=/usr
<cut>

Configure summary:

        mate-terminal 1.25.0
        ====================

    prefix:                 /usr
    source code location:   .
    compiler:               gcc
    cflags:                 
    warning flags:          -Wall -Wmissing-prototypes
    linker flags:           

    smclient support:       yes
    s/key support:          yes

Now type `make' to compile mate-terminal