Fix memory leaks using Valgrind

Coccinella consumes a lot of memory. Probably the used libraries are responsible for some part. Fixing these leaks will reduce Coccinella's memory usage which will be a good thing, especially on mobile devices with few memory available.

I tried myself and as you can see in the summary, there are some leaks to fix...
$ valgrind --tool=memcheck --leak-check=yes ./Coccinella-0.96.4.1.bin

<snip>

==23893== LEAK SUMMARY:
==23893== definitely lost: 46,018 bytes in 92 blocks.
==23893== indirectly lost: 5,668 bytes in 111 blocks.
==23893== possibly lost: 20,632 bytes in 9 blocks.
==23893== still reachable: 9,905,294 bytes in 120,879 blocks.
==23893== suppressed: 0 bytes in 0 blocks.
==23893== Reachable blocks (those to which a pointer was found) are not shown.
==23893== To see them, rerun with: --leak-check=full --show-reachable=yes

(when testing, I started Coccinella, logged in, and quit using the File menu...so there may be more leaks in other locations!)

URL: http://valgrind.org/