Explicitly set the encoding to UTF-8.

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project core: Compilation failure: Compilation failure:
[ERROR] bootstrap class path not set in conjunction with -source 1.6
[ERROR] /home/ferdy/src/Alitheia-Core/alitheia/core/src/main/java/eu/sqooss/service/fds/FileTypeMatcher.java:[123,54] error: unmappable character for encoding ASCII
[ERROR] /home/ferdy/src/Alitheia-Core/alitheia/core/src/main/java/eu/sqooss/service/fds/FileTypeMatcher.java:[123,55] error: unmappable character for encoding ASCII
[ERROR] /home/ferdy/src/Alitheia-Core/alitheia/core/src/main/java/eu/sqooss/service/fds/FileTypeMatcher.java:[123,56] error: unmappable character for encoding ASCII