cmake: fixed version handling

VERSION_MAJOR = 1

VERSION_MINOR = 9

PATCHLEVEL = 99

VERSION_TWEAK = 0

EXTRAVERSION =

# from https://gist.github.com/korzo89/71a6de0f388f7cf8b349101b0134060c

function(from_hex HEX DEC)

    string(SUBSTRING "${HEX}" 2 -1 HEX)

    string(TOUPPER "${HEX}" HEX)

    set(_res 0)

    string(LENGTH "${HEX}" _strlen)

    while(_strlen GREATER 0)

        math(EXPR _res "${_res} * 16")

        string(SUBSTRING "${HEX}" 0 1 NIBBLE)

        string(SUBSTRING "${HEX}" 1 -1 HEX)

        if(NIBBLE STREQUAL "A")

            math(EXPR _res "${_res} + 10")

        elseif(NIBBLE STREQUAL "B")

            math(EXPR _res "${_res} + 11")

        elseif(NIBBLE STREQUAL "C")

            math(EXPR _res "${_res} + 12")

        elseif(NIBBLE STREQUAL "D")

            math(EXPR _res "${_res} + 13")

        elseif(NIBBLE STREQUAL "E")

            math(EXPR _res "${_res} + 14")

        elseif(NIBBLE STREQUAL "F")

            math(EXPR _res "${_res} + 15")

        else()

            math(EXPR _res "${_res} + ${NIBBLE}")

        endif()

        string(LENGTH "${HEX}" _strlen)

    endwhile()

    set(${DEC} ${_res} PARENT_SCOPE)

endfunction()

function(to_hex DEC HEX)

    while(DEC GREATER 0)

        math(EXPR _val "${DEC} % 16")

        math(EXPR DEC "${DEC} / 16")

        if(_val EQUAL 10)

            set(_val "A")

        elseif(_val EQUAL 11)

            set(_val "B")

        elseif(_val EQUAL 12)

            set(_val "C")

        elseif(_val EQUAL 13)

            set(_val "D")

        elseif(_val EQUAL 14)

            set(_val "E")

        elseif(_val EQUAL 15)

            set(_val "F")

        endif()

        set(_res "${_val}${_res}")

    endwhile()

    set(${HEX} "0x${_res}" PARENT_SCOPE)

endfunction()