Add note about increasing trim cache size
* Make requirement checks report their result with `-v`.
* Fix verbose prints to use the fwup_warn helper instead of calling fprintf
directely. (Cleanup)
+ * Enlarged trim cache for up to 64 GiB memory devices. Large ones will work,
+ but trim caching is ignored after 64 GiB. This should almost all known
+ uses of fwup now. The use of fwup on large SSDs still works, since fwup
+ is pretty much only used at lower offsets.
## v0.15.3
