abuild.conf: added JOBS variable

makes it easier to support parallel builds on non gnu make system

abuild.conf

@@ -6,7 +6,8 @@ export LDFLAGS="-Wl,--as-needed"
 
 export PATH=:/usr/i386-gentoo-linux-uclibc/binutils-bin/2.18:$PATH
 
-export MAKEFLAGS=-j2
+export JOBS=2
+export MAKEFLAGS=-j$JOBS
 
 # remove line below to disable colors
 USE_COLORS=1