Ok, another try! Now I edited Tectonicus.*.jar and replaced the files in the "native" folder, so the actual files of lwjgl are stored in. The bug, that he can't find libjawt.so, still exists. libjawt.so in stored in /usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64/libjawt.so, but in /usr/lib/ is the file missing, so I linked it to the one in java-7-openjdk. Now there's another bug known from Ubuntu 11.04 with openjdk-6-jre:
Forcing 64-bit native libraries
Player skin cache is old or corrupt, cleaning...
Creating player icon assembler
Initialising display...
Exception in thread "main" java.lang.UnsatisfiedLinkError: /home/server/.tectonicus/native/liblwjgl.so: /usr/lib/libjawt.so: symbol awt_Unlock, version SUNWprivate_1.1 not defined in file libmawt.so with link time reference
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1924)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1821)
at java.lang.Runtime.load0(Runtime.java:792)
at java.lang.System.load(System.java:1059)
at org.lwjgl.Sys$1.run(Sys.java:70)
at java.security.AccessController.doPrivileged(Native Method)
at org.lwjgl.Sys.doLoadLibrary(Sys.java:66)
at org.lwjgl.Sys.loadLibrary(Sys.java:82)
at org.lwjgl.Sys.<clinit>(Sys.java:99)
at org.lwjgl.opengl.Display.<clinit>(Display.java:130)
at tectonicus.rasteriser.lwjgl.LwjglRasteriser.<init>(LwjglRasteriser.java:110)
at tectonicus.rasteriser.RasteriserFactory.createRasteriser(RasteriserFactory.java:24)
at tectonicus.TileRenderer.<init>(TileRenderer.java:146)
at tectonicus.TectonicusApp.run(TectonicusApp.java:808)
at tectonicus.TectonicusApp.main(TectonicusApp.java:1173)
It's the awt_Unlock-bug... -.- That's so depressingly...