Fix references to the no-longer-existent misc/ directory in comments, README files, and documentation

THTTPD: Remove use of lstat when directory indexing is enabled.  NuttX does not support symbolic links

Fix a few errors/warnings in THTTPD when indexing is enabled.  Still depends on non-existent lstat and ctime

Lincoln60: Add a thttpd-binfs configuration.  That configuration still does not work on initial commit

Damn.  THTTPD will not yet run with binfs because it wants an index.html file.  THTTPD does support indexing directories if CONFIG_THTTPD_GENERATE_INDICES=y, but there are some compilation issues that need to be fixed when that option is selected.