Java/File: fix include guard
android: switch to gcc 4.9 / llvm 3.5 (NDK r10c)
android: release v0.19.4

Android releases were missing since 0.19.1.
configure.ac: prepare for 0.19.5
doc/protocol: mention that "count" can have multiple filters
decoder/{dsdiff,dsf,opus}: fix deadlock while seeking
Merge branch 'v0.19.x'