Quote paths so build scripts work when directories have space in their name.

Currently if you clone Marlin to a directory with a space in the name, Arduino will generate an error.
Because when executed the path ends up split into two separate arguments.

ArduinoAddons/Arduino_1.5.x/hardware/marlin/avr/platform.local.txt

@@ -1,2 +1,2 @@
 compiler.cpp.extra_flags=-DHAS_AUTOMATIC_VERSIONING
-recipe.hooks.prebuild.pattern=/usr/local/bin/generate_version_header_for_marlin {build.source.path} {build.path}/_Version.h
+recipe.hooks.prebuild.pattern=/usr/local/bin/generate_version_header_for_marlin "{build.source.path}" "{build.path}/_Version.h"

LinuxAddons/bin/generate_version_header_for_marlin

@@ -1,18 +1,18 @@
 #!/usr/bin/env bash
 # generate_version_header_for_marlin
 
-DIR=$1 export DIR
-OUTFILE=$2 export OUTFILE
-echo "/* This file is automatically generated by an Arduino hook" >$OUTFILE
-echo " * Do not manually edit it" >>$OUTFILE
-echo " * It does not get committed to the repository" >>$OUTFILE
-echo " */" >>$OUTFILE
-echo "" >>$OUTFILE
+DIR="$1" export DIR
+OUTFILE="$2" export OUTFILE
+echo "/* This file is automatically generated by an Arduino hook" >"$OUTFILE"
+echo " * Do not manually edit it" >>"$OUTFILE"
+echo " * It does not get committed to the repository" >>"$OUTFILE"
+echo " */" >>"$OUTFILE"
+echo "" >>"$OUTFILE"
 
-echo "#define BUILD_UNIX_DATETIME" `date +%s` >>$OUTFILE
-echo "#define STRING_DISTRIBUTION_DATE" `date '+"%Y-%m-%d %H:%M"'` >>$OUTFILE
+echo "#define BUILD_UNIX_DATETIME" `date +%s` >>"$OUTFILE"
+echo "#define STRING_DISTRIBUTION_DATE" `date '+"%Y-%m-%d %H:%M"'` >>"$OUTFILE"
 ( set +e
-  cd $DIR
+  cd "$DIR"
   BRANCH=`git symbolic-ref --short HEAD`
   if [ "x$BRANCH" == "xHEAD" ] ; then
     BRANCH=""
@@ -23,13 +23,13 @@ echo "#define STRING_DISTRIBUTION_DATE" `date '+"%Y-%m-%d %H:%M"'` >>$OUTFILE
   fi
   VERSION=`git describe --tags --first-parent 2>/dev/null` 
   if [ "x$VERSION" != "x" ] ; then
-    echo "#define BUILD_VERSION \"$VERSION\"" | sed "s/-/$BRANCH-/" >>$OUTFILE
+    echo "#define BUILD_VERSION \"$VERSION\"" | sed "s/-/$BRANCH-/" >>"$OUTFILE"
   fi
   URL=`git config --local --get remote.origin.url | sed "sx.*github.com:xhttps://github.com/x" | sed "sx\.gitx/x"`
   if [ "x$URL" != "x" ] ; then
-    echo "#define SOURCE_CODE_URL  \""$URL"\"" >>$OUTFILE
-    echo "// Deprecated URL definition" >>$OUTFILE
-    echo "#define FIRMWARE_URL  \""$URL"\"" >>$OUTFILE
+    echo "#define SOURCE_CODE_URL  \""$URL"\"" >>"$OUTFILE"
+    echo "// Deprecated URL definition" >>"$OUTFILE"
+    echo "#define FIRMWARE_URL  \""$URL"\"" >>"$OUTFILE"
   fi
   
 )