beesh: fix check_rebuild

packages containing '+' did not work properly:

[BEE] package  already exists: /home/ruester/.local/src/bee/packages/gtk+-3.0.5-0.x86_64.bee.tar.bz2
[BEE] bee-file already exists: /home/ruester/.local/src/bee/bee-files/gtk+-3.0.5-0.bee
[BEE] please increase revision number
usage: beeversion <package>
[BEE] cp /home/ruester/git/bee.git/./gtk+-3.0.5-0.bee /home/ruester/git/bee.git/gtk+-3.0.5-1.bee

so now we prepare ${beefile_pattern} to be a regular expression by escaping
the characters + and . to \+ and \.

src/beesh.sh.in

@@ -145,13 +145,16 @@ function check_rebuild() {
     eval $(${BEEVERSION} ${beefile})
 
     beefile_pattern="${PKGFULLNAME}-${PKGFULLVERSION}"
+    beefile_pattern=${beefile_pattern//+/\\+} # replace all + with \+
+    beefile_pattern=${beefile_pattern//./\\.} # replace all . with \.
+
     beefile_max=$(for bf in $(ls ${beefile%/*}/${beefile_pattern}*.bee ${BEE_BEEDIR}/${beefile_pattern}*.bee 2>/dev/null |\
                               grep -E "/${beefile_pattern}-[0-9]+.bee") ; do
                       echo "${bf}"
                   done | ${BEESORT} | tail -1)
 
     eval $(${BEEVERSION} ${beefile_max})
-    print_warning "cp ${beefile} ${PWD}/${beefile_pattern}-$((PKGREVISION + 1)).bee"
+    print_warning "cp ${beefile} ${PWD}/${PKGFULLNAME}-${PKGFULLVERSION}-$((PKGREVISION + 1)).bee"
 
     exit 1
 }