[chirp_devel] Information Prompt Patch

OK, mercurial has been giving me fits trying to split these changesets out. So here is a combined patch with the diffs for chirp_common, mainapp and the lt725uv driver. All in support of issue #5889, adding the information prompt at download. I'm still trying to get the ft450d driver change (adding the info prompt verbage) to process, keep getting - "abort: working directory revision is not qtip" from the "hg qnew -ef ft450d_info" cmd.