Resolves the following clang-10 compiler warnings:
```
$ ninja
[65/177] Building CXX object examples/CMakeFiles/oit.dir/oit/oit.cpp.o
../examples/oit/oit.cpp:501:7: warning: 'buildCommandBuffers' overrides a member function but is not marked 'override' [-Winconsistent-missing-override]
void buildCommandBuffers()
^
../base/vulkanexamplebase.h:351:15: note: overridden virtual function is here
virtual void buildCommandBuffers();
^
1 warning generated.
[78/177] Building CXX object examples/CMakeFiles/inlineuniformblocks.dir/inlineuniformblocks/inlineuniformblocks.cpp.o
../examples/inlineuniformblocks/inlineuniformblocks.cpp:19:27: warning: implicit conversion from 'int' to 'float' changes value from 2147483647 to 2147483648 [-Wimplicit-int-float-conversion]
return ((float)rand() / (RAND_MAX));
~ ^~~~~~~~
/usr/include/stdlib.h:86:18: note: expanded from macro 'RAND_MAX'
^~~~~~~~~~
1 warning generated.
[84/177] Building CXX object examples/CMakeFiles/pushconstants.dir/pushconstants/pushconstants.cpp.o
../examples/pushconstants/pushconstants.cpp:24:28: warning: implicit conversion from 'int' to 'float' changes value from 2147483647 to 2147483648 [-Wimplicit-int-float-conversion]
return ((float) rand() / (RAND_MAX));
~ ^~~~~~~~
/usr/include/stdlib.h:86:18: note: expanded from macro 'RAND_MAX'
^~~~~~~~~~
```
* Add Order Independent Transparency example
* Update README.md
* Add copyright at Order Independent Transparency example
* Disable the validation by default
