Added GNU Lesser General Public License version 2.1 blurb to Makefile
Added GNU Lesser General Public License version 2.1 blurb to Makefile

Copied from mce.h under assumption that the Makefile is covered by the same
license as the source code it is used to compile.

mikkoharju/mce,maikelwever/mce,kimmoli/mce,maikelwever/mce,mlehtima/mce,spiiroin/mce,kimmoli/mce,spiiroin/mce,mikkoharju/mce,maikelwever/mce,maikelwever/mce,android-808/mce,kimmoli/mce,spiiroin/mce,mlehtima/mce,mlehtima/mce,kimmoli/mce,android-808/mce,android-808/mce,mlehtima/mce,spiiroin/mce,mikkoharju/mce,android-808/mce,mikkoharju/mce