More intuitive version matching

[Roy-Orbison]

Avoids many issues with regex and glob patterns in version arguments matching incorrectly. Prevents invalid versions being requested from remote source. Always provides opportunity to confirm version being installed.

Fixes #58.

[Roy-Orbison]

For testing, I have been using these extra lines to avoid thrashing & waiting for the remote:

diff --git a/ubuntu-mainline-kernel.sh b/ubuntu-mainline-kernel.sh
index fc9c0c3..f60f946 100755
--- a/ubuntu-mainline-kernel.sh
+++ b/ubuntu-mainline-kernel.sh
@@ -369,6 +369,7 @@ latest_local_version() {
 }

 remote_html_cache=""
+remote_html_cache="$(cat < remote_html_cache)"
 remote_versions_read=0

 normalize_version_for_match() {
@@ -412,6 +413,7 @@ load_remote_versions () {
         if [ -z "$remote_html_cache" ]; then
           [ -z "$2" ] && logn "Downloading index from $ppa_host"
           remote_html_cache=$(download $ppa_host $ppa_index)
+          cat <<<"$remote_html_cache" > remote_html_cache
           [ -z "$2" ] && log
         fi

@@ -609,6 +611,7 @@ Optional:
         else
             log
         fi
+        exit

         [ ! -d "$workdir" ] && {
             mkdir -p "$workdir" 2>/dev/null

I used commands like these:

./ubuntu-mainline-kernel.sh -r 4.19 --rc

./ubuntu-mainline-kernel.sh -i 4.19 -do