Performance improvements in FileUtils / TextureCache

Added common "apple" platform to avoid duplicate files in FileUtils and other common files
Improves performance in fetching files.
lazy alloc component container

faster and less memory
Removes some Hungarion notation...

...and improves performance in FileUtils: String is not created
little optimization.

string is created when needed
compatible with cocos2d c++ guidelines
Key should start with '/' to gain performance

Signed-off-by: Ricardo Quesada <ricardoquesada@gmail.com>
Adds const in FileUtils

`const` was missing in some getters

Signed-off-by: Ricardo Quesada <ricardoquesada@gmail.com>
Optimization + standardization in FileUtils

Since `FileUtils` was using `std::string` internally, it is more efficient to accept `const std::string &` as parameter than `char *` to avoid the creation of unneeded strings.

Signed-off-by: Ricardo Quesada <ricardoquesada@gmail.com>
Replaces `Dictionary` with `std::unordered_map`

I did some performance tests, and `std::unordered_map` is more performant than `Dictionary`.

I need to do more tests, but so far, the results are good.

Signed-off-by: Ricardo Quesada <ricardoquesada@gmail.com>
snapshopTextures are no longer supported

Signed-off-by: Ricardo Quesada <ricardoquesada@gmail.com>
Merge pull request #3554 from ricardoquesada/fileutils_perf_improvements

Fileutils perf improvements