This commit changes the way libraries headers are included in source files:
- If the header is in the same directory the source belongs to, so the
notation '#include ""' is used with the path relative to the directory
containing the source.
- If the header is outside the directory containing the source, then we use
the notation '#include <>' with the path relative to libraries folder.
Some of the advantages of such approach:
- Only one search path for libraries headers.
- OSs like Windows may have a better lookup time.
Support for File System starage mode is retained, appropriate Storage
mode can be set by defining USE_FS_STORAGE for File System storage
aand US_FRAM_STORAGE for FRAM storage. Note: FS storage and FRAM
storage are never synced as of now.