I run minecraft with forge and the launcher doesn't make nothing.
I noticed that in .minecraft\versions\ only has a 1.7.10-Forge10.13.4.1492-1.7.10.json file, would not have to have also an .jar, in 1.8 also
I tried this method and it worked on 1.7.10 but only with Forge # 1208
http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/2206446-forge-1-6-4-1-7-2-java-8-compatibility-patch
with -Xmx1G -Dforge.forceNoStencil=true