Fix some problems to compile on Linux

[superboum]

1. Case must be respected on case sensitive filesystems (like ext4 or HFS+ configured as case sensitive) otherwise compilation fails for modules and headers files.
2. Local addons shouldn't be included in addons.make, otherwise it crashes the build.

Not included in the Pull Request :

1. Linking against alsa with -lasound is needed on Linux. I didn't understand why it's not automatically done nor where to add it. I put it in config.make but it might cause regression on MacOS, that's why I didn't included this fix in my PR.

[ofZach]

thx for the changes! it should probably be in there as "addons/ofxMidi" along with the other local addons with their path from the root level (root folder)

[superboum]

I should miss something. This what I typed :

rm -rf obj
make clean
make Debug -j8

But the compilation failed on every tries:

1. If the root level means the root level of my app, I should put addons/ofxMidi indeed, but I get many errors like the following (already defined):

/home/qdufour/Documents/dev/cpp/of_v0.9.8_linux64_release/apps/myApps/recoded/addons/ofxMidi/src/ofxMidiOut.cpp:14 : multiples definition of « ofxMidiOut::ofxMidiOut(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) »
obj/linux64/Debug/addons/ofxMidi/src/ofxMidiOut.o:/home/qdufour/Documents/dev/cpp/of_v0.9.8_linux64_release/apps/myApps/recoded/addons/ofxMidi/src/ofxMidiOut.cpp:14 : first defined here

Full content of addons.make :

ofxGui
ofxXmlSettings
ofxOsc
addons/ofxMidi
addons/ofxParameterMidiSync
addons/ofxTween

I've the same error if I put /addons/ofxMidi

2. If the root level, means the root level of OpenFrameworks directory, I should put apps/myApps/recoded/addons/ofxMidi but I get the following error:

Compiling recoded for Debug
make[1] : on entre dans le répertoire « /home/qdufour/Documents/dev/cpp/of_v0.9.8_linux64_release/apps/myApps/recoded »
HOST_OS=Linux
checking pkg-config libraries:   cairo zlib gstreamer-app-1.0 gstreamer-1.0 gstreamer-video-1.0 gstreamer-base-1.0 libudev freetype2 fontconfig sndfile openal openssl gl glu glew gtk+-3.0 
find: ‘unused’: No such file or directory
find: ‘unused’: No such file or directory
make[1]: execvp: /bin/sh : Argument list too long
make[1]: *** [/home/qdufour/Documents/dev/cpp/of_v0.9.8_linux64_release/libs/openFrameworksCompiled/project/makefileCommon/compile.project.mk:190: obj/linux64/Debug/.compiler_flags] Error 127
make[1] : on quitte le répertoire « /home/qdufour/Documents/dev/cpp/of_v0.9.8_linux64_release/apps/myApps/recoded »
make: *** [/home/qdufour/Documents/dev/cpp/of_v0.9.8_linux64_release/libs/openFrameworksCompiled/project/makefileCommon/compile.project.mk:147: Debug] Error 2

Full content of addons.make :

ofxGui
ofxXmlSettings
ofxOsc
apps/myApps/recoded/addons/ofxMidi
apps/myApps/recoded/addons/ofxParameterMidiSync
apps/myApps/recoded/addons/ofxTween

I've the same error if I put /apps/myApps/recoded/addons/ofxMidi