* Integrated filesystem operation abstraction code into filesystem.cpp
* Modified filesystem unit tests to be more platform agnostic
* Added append mode for PlatformFile
* Minor bug fixes in filesystem operations
Some of the types in fileops tests were causing warnings to be thrown
during build, due to type mismatch. I've added a few local variables to
quiet these warnings.
* Implemented filesystem operations abstraction code
* Added filesystem operations abstraction unit tests
* Modified CMake configurations to support the building of the abstraction code and unit tests
There are 3 new options that control how files are read:
--read_max: controls the maximum size, in bytes, for file reads. If a file is larger than `read_max` the read will fail.
--read_user_max: similar to `read_max` but applies additional limitations to user-controlled files.
--read_user_links: a boolean control to enable/disable following symlinks for user-controlled files.
Important highlights:
If files exceed the configured max, those reads will fail.
The `read_max` will override `read_user_max` if it is set lower.
A default integer value of `0` will disable the limitations.
The default `read_max` is set to 50M and the default `read_user_max` is 10M.
POSIX-globbing will allow event publishers/subscribers to post-check
results against glob-syntax, fnpath matching, and POSIX C-regex.
These checks are anecdotally speedy.
