Merge pull request #752 from esparta/master

[es] Removing duplicates & added book about concurrent programming
Fix ordering in C++ section
Remove superfluous whitespace
Add QML section and Qt5 Cadaques book
Merge pull request #753 from dstftw/master

Tidy the list and add Qt5 Cadaques book
two books added

for c and c++
Merge pull request #754 from varanus/master

german book list corrections
[es] Adding a El camino a un mejor programador