[SwapCheck] add global swap check component, this will allow any function to check if a temp swapfile should be created.

only basic atm, but in future there will be an option to set the size of swapfile, and how much free RAM is required.
for an example how to use see this commit https://github.com/oe-alliance/XMTV-Import/commit/6f19a8a75d2287696096e2bcc8c9f064ba2c7de6