Add experimental "trigram" tokenizer to fts5.

FossilOrigin-Name: c4e8ec7907de7cb9e610ef9f4930caf5c046618151fb4f61d5716b9fa3f31423

diff --cc manifest
index aee1d7da6709cdcd1ce5ad0bfc05e5ee38dfc784,c82a29968454290a99718d41dabe26286885fcb0..acf1e33d84635e32eadfd78af1822c30537f6704
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Fix\sthe\sOP_SeekScan\sopcode\sso\sthat\sits\svariable\snames\sdo\snot\scause\sproblems\nfor\sthe\stest/vdbe-compress.tcl\sscript.
- D 2020-10-01T15:46:21.737
 -C Add\sthe\s-trigram\soption\sto\sthe\sfts5txt2db.tcl\sscript.
 -D 2020-10-01T17:15:12.635
++C Add\sexperimental\s"trigram"\stokenizer\sto\sfts5.
++D 2020-10-01T17:24:36.768
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
  F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@@ -1880,7 -1882,7 +1882,8 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
  F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
- P e9d1efa597fb073dc4bc4286e03059a350ed05d3e6476cd3247e6cde626f458b
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++R 104c9174ee4e67de5600298bebaefb92
++T +closed a394dd260252e7b7dcbc90fd321dfd40d9375f0598ea52b01001c568cbdbafce
+ U dan
 -Z 2da13f86d1d686cfa74ee427cae5fd66
++Z 65fad92c1f5f48b452b431c90b403063

diff --cc manifest.uuid
index 73933d068312325c48ffaf47498d70a282ae5dc1,6e00578a5caa748af1a65c09783b083719d09d9d..7a27efdb1db70e3aeaf05a1ad716b46df942ffd2
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 7a78274a072324b94d6f79e5b7a198b2fa9321ff5d6a528b51f57d3ee95c765b
 -a394dd260252e7b7dcbc90fd321dfd40d9375f0598ea52b01001c568cbdbafce
++c4e8ec7907de7cb9e610ef9f4930caf5c046618151fb4f61d5716b9fa3f31423