Add the "PRAGMA table_xinfo" command that works like table_info but also

shows hidden columns in virtual tables and adds the "hidden" boolean column.

FossilOrigin-Name: defa0515b8fd50ed9be699542f8c6695dd4a60c02f310665db6657ec5b6b67d0

diff --cc manifest
index 8c7dc3492191922225d3a1d2cfdd4e4991239a61,7febae11fae2685ed0fe02eb0651a3cad6e941b3..87e065761148b7ce54139595ce1c110ecb2fe58c
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Speed\sup\sxAccess()\scalls\smade\son\san\sRBU\sVFS\swhen\sthere\sare\slots\sof\sopen\nconnections.
- D 2018-10-01T17:33:35.846
 -C Test\scase\sfor\sPRAGMA\stable_xinfo.
 -D 2018-10-01T21:36:38.715
++C Add\sthe\s"PRAGMA\stable_xinfo"\scommand\sthat\sworks\slike\stable_info\sbut\salso\nshows\shidden\scolumns\sin\svirtual\stables\sand\sadds\sthe\s"hidden"\sboolean\scolumn.
++D 2018-10-01T21:41:15.265
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
  F Makefile.in 01e95208a78b57d056131382c493c963518f36da4c42b12a97eb324401b3a334
@@@ -1770,7 -1770,7 +1770,8 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
  F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
- P 8ac2cdda68f92b0352bc7f0b4be5fca4bb58565ca65055fb34153cc284ed6922
- R a63f057a754c642de8f2617ecd7043d5
- U dan
- Z c6e86f7777ba1872e2992f69103701bb
 -P 2fdd068987e59b979045d71ae64e700600ef07e54ae340f30c2064e5dcccb8ea
 -R f25affb049e7e387101b1afc916c6b2e
++P 310b4b65b8c8ee080760c7efb4c7e20244c6063a5dba37a4f40490105aafd29f 7694b9bc3003db6ba0b41c5029c8f7b84c07724e7a518e835e98b3c46e4ea227
++R 4421b937cd53dd313f71ab5caa0a0109
++T +closed 7694b9bc3003db6ba0b41c5029c8f7b84c07724e7a518e835e98b3c46e4ea227
+ U drh
 -Z 9b806ae5358896ee00b1faf1a3216949
++Z e0b06ff9de331820a7420ba45b53f562

diff --cc manifest.uuid
index 8b77660070ef6f6337dcbbee2f5e091d50c3f6d9,02ce067f824261e1da62b82e1ef497f208883d2f..b4be3bca8ba4da3a5fad46a2d618b444cc2b4cbc
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 310b4b65b8c8ee080760c7efb4c7e20244c6063a5dba37a4f40490105aafd29f
 -7694b9bc3003db6ba0b41c5029c8f7b84c07724e7a518e835e98b3c46e4ea227
++defa0515b8fd50ed9be699542f8c6695dd4a60c02f310665db6657ec5b6b67d0