TODO

command line ui:
  * support relative paths in command line!
  * show sub-command list in help output (only works in repo mode atm)
  * validate() can't validate argv()
  * Improve help output.. should show "vmprobe [cmd] <args>" example template

curses ui:
  probe screens:
    needs latest:
      * real-time file list
      * super expanded version of file that takes up whole screen
    needs history
      * history of single file
      * real-time file-based deltas
      * snapshot history viewer
  ? paged scrolling

snapshots:
  ! should catch SIGBUS while faulting in pages from mmap - file could get truncated
  ! nicely report errors like permissions problems
  ! detect duplicate hard-links in crawler.cpp
  * use SSE and whatnot to speed up snapshot operations
  * optimize load order for HDDs, handle sparse files (FS_IOC_FIEMAP) (see ureadahead)
  * subsume mincore builder into pagemap builder (since it calls mincore anyway)
  ? Does it make sense to read from pagemap/kpageflags in batches to reduce memory usage?
  ? use readahead(2) on linux? MAP_POPULATE?
  ? wildcard globbing