master updated (17188e07ab9 -> 7f5a2d0a251)

[Jim Porter]

jporter pushed a change to branch master.

      from  17188e07ab9 Don't push to Xref history when search ends with error
       new  ccb62321d23 Fix handling of Eshell debug modes
       new  7f5a2d0a251 Add debug instrumentation for Eshell process management


Summary of changes:
 doc/misc/eshell.texi                     |  21 +++++--
 lisp/eshell/em-basic.el                  |  32 ++++++++++
 lisp/eshell/esh-cmd.el                   | 105 +++++++------------------------
 lisp/eshell/esh-proc.el                  |  17 ++++-
 lisp/eshell/esh-util.el                  |  45 +++++++++++--
 lisp/eshell/eshell.el                    |   3 +-
 test/lisp/eshell/eshell-tests-helpers.el |  31 ++++++---
 7 files changed, 153 insertions(+), 101 deletions(-)