core::Engine: Fix memory leaks, misc

[mckelvin]

this PR consists of 2 parts;

1. fix compilation error while compiling using llvm(clang++ ) as reference to 'end' is ambiguous in llvm.
2. fix memory leaks in core::Engine, the following code may be useful to prove that the memory leak do exists while reload DataFlow again and again:

import resource
from yaafelib import Engine, FeaturePlan

def main():
    fp = FeaturePlan()
    fp.addFeature("mfcc: MFCC blockSize=1024 stepSize=1024 CepsNbCoeffs=11")
    df = fp.getDataFlow()

    for i in range(10):
        for j in range(100):
            eng = Engine()
            eng.load(df)
        print i, resource.getrusage(resource.RUSAGE_SELF).ru_maxrss

if __name__ == '__main__':
    main()

the output is something like:

0 19640
1 22808
2 25712
3 28616
4 31784
5 34688
6 37592
7 40760
8 43664
9 46568

if no memory leaks happened, it should be something like:

0 19640
1 19640
2 19640
...

I've check and test the code. Please review it again!

BTW, I use the great tool valgrind to find the leak code.

[thomasfillon]

@mckelvin : Thank you very much for this PR !

We will review it as soon as possible !

[mckelvin]

Hi, @thomasfillon the PR has been pending for more than 3 weeks, I wonder if you have forgotten this. I've already merged this branch into my own repo's master branch. @seansay and I plan to add some more features into Yaafe to make it even better. Actually there are ready some heavy changes, I wonder if these changes are welcomed. ;)

[thomasfillon]

OK the merge is done. Sorry for the delay and thank you again for this PR.
And by the way, the changes are very welcomed ;)

[mckelvin]

It's not relevant with this pull, but forgive me, I don't where else to post.

https://github.com/Yaafe/Yaafe/blob/master/src_cpp/yaafe-python/yaafecore.cpp#L102 looks like a bug

[thomasfillon]

Thank you very much. I will open an issue on that

[AM237]

Hi all, not sure if I'm missing something, but valgrind still reports ~5KB of leaked memory on a single (successful) run of yaafe-engine. Is this currently being tackled? Thanks!

[mckelvin]

@AM237 #4 has fixed fix memleaks in: Smarc, MP3FileReader, freeOutputFormatDescription, but there should be some other memleaks including [here].(https://github.com/Yaafe/Yaafe/blob/master/src_cpp/yaafe-core/OutputFormat.cpp#L65 )