Fix to cause BtShared.db to be set correctly on shared-cache

connections in SQLITE_THREADSAFE=0 builds.  Added assert()s to verify
the correct setting of BtShared.db.

FossilOrigin-Name: 2d96aeba2460779a0a20356739a0ba49144c8a85

diff --cc manifest
index b3a7209f04c9120a0992d238ef3d8b88200960be,6af226d61ce14101e32abe0c7ba602c16d6f6245..1f5fbe7bdd0d0749ee9e785ce80e1977cc4da037
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Small\sperformance\sand\ssize\soptimization\sspotted\swhile\sworking\son\sthe\nshared-cache\sproblem.
- D 2016-01-07T17:09:43.631
 -C Add\ssome\sassert()\sstatements\sto\sverify,\swhere\spossible,\sthat\sBtShared.db\sis\sset\scorrectly.
 -D 2016-01-07T16:43:54.695
++C Fix\sto\scause\sBtShared.db\sto\sbe\sset\scorrectly\son\sshared-cache\nconnections\sin\sSQLITE_THREADSAFE=0\sbuilds.\s\sAdded\sassert()s\sto\sverify\nthe\scorrect\ssetting\sof\sBtShared.db.
++D 2016-01-07T17:19:24.484
  F Makefile.in 7c8cc4c2f0179efc6fa9492141d1fb65f4807054
  F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
  F Makefile.msc e45d8b9b56dfa3f2cd860b2c28bd9d304513b042
@@@ -275,11 -275,11 +275,11 @@@ F src/attach.c e944d0052b577703b9b83aac
  F src/auth.c b56c78ebe40a2110fd361379f7e8162d23f92240
  F src/backup.c 2869a76c03eb393ee795416e2387005553df72bc
  F src/bitvec.c 1a78d450a17c5016710eec900bedfc5729bf9bdf
- F src/btmutex.c 45a968cc85afed9b5e6cf55bf1f42f8d18107f79
- F src/btree.c 4d3452b2a3daf875490ac4f0a278da7f85fabe12
- F src/btree.h 2d76dee44704c47eed323356a758662724b674a0
+ F src/btmutex.c bc87dd3b062cc26edfe79918de2200ccb8d41e73
+ F src/btree.c 09ec3ca5e7a6b8c277cef6c4471a1427cab5fa01
+ F src/btree.h 68ef301795e00cdf1d3ab93abc44a43b7fe771e0
  F src/btreeInt.h b5f2651b41808f038dee9282c5dc0232ce6532d3
 -F src/build.c d8006e9030c61b9495d0b2f724edd3fcdae16930
 +F src/build.c 9d497ff4bf3c82cecb520436e0e9963785627583
  F src/callback.c 7b44ce59674338ad48b0e84e7b72f935ea4f68b0
  F src/complete.c addcd8160b081131005d5bc2d34adf20c1c5c92f
  F src/ctime.c 60e135af364d777a9ab41c97e5e89cd224da6198
@@@ -1406,7 -1406,7 +1406,8 @@@ F tool/vdbe_profile.tcl 246d0da094856d7
  F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
  F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
  F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
- P 4f80440bf566959306f6ca8cbb1fd29d138ee38b
- R f265718df82e1345668e0777962739f6
 -P d0214602d44d6b84b7463d530720e2560aee6edf
 -R d2d125340e47dee2c161777b81c6bca6
 -U dan
 -Z cf8789ac325f523b3a85068e24d5a916
++P 828958ff77a5c239d55302f570077835c093e0fa 359277e0e5338f6d7743d58cf99e1c934a8460d5
++R 6a20a209200c5a1c13b83cee78194e2e
++T +closed 359277e0e5338f6d7743d58cf99e1c934a8460d5
 +U drh
- Z e6c791f6b7ef0a212def33d53e341994
++Z 1846b22def634146b1c38f34bfdda1cc

diff --cc manifest.uuid
index 64d2588352e8fd410cc192b0d55d854f22ddc2b9,0775299b73edace1bfe940c2afd6134400a99f9b..d6aa2d2612a02b0eb52b3d029ccdc4d304794b72
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 828958ff77a5c239d55302f570077835c093e0fa
 -359277e0e5338f6d7743d58cf99e1c934a8460d5
++2d96aeba2460779a0a20356739a0ba49144c8a85