/ Changes On Branch user-auth

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Changes In Branch user-auth Excluding Merge-Ins

This is equivalent to a diff from ad7063aa1a to b149ef5c63

Add the SQLITE_USER_AUTHENTICATION extension to the trunk. This extension is disabled by default. Special compilation procedures are need to enable it. (check-in: 65884d4f81 user: drh tags: trunk)
Clean up some #includes in the extension API implementation. (Closed-Leaf check-in: b149ef5c63 user: drh tags: user-auth)
Suppress the potential schema error that occurs when a non-user-auth SQLite library tries to parse the sqlite_user table definition in a user-auth database. (check-in: cda33c1ef3 user: drh tags: user-auth)
Add new APIs that take 64-bit length parameters: sqlite3_malloc64(), sqlite3_realloc64(), sqlite3_bind_blob64(), sqlite3_bind_texte64(), sqlite3_result_blob64(), and sqlite3_result_texte64(). Internal memory allocation routines also now use 64-bit unsigned length parameters for safety. Also add the sqlite3_msize() interface. Fix the sqlite3_get_table() to use sqlite3_realloc64() to avoid a integer overflow problem. (check-in: 94954850cf user: drh tags: 64-bit-lengths)
Non-working preliminary implementation attempts on user authentication. (check-in: 8440f093ba user: drh tags: user-auth)
Merge support for large files on Android from trunk. (check-in: c2885c6bb2 user: drh tags: sessions)
Fixes to os_unix.c to support database (and other) files larger than 2GiB on Android. (check-in: ad7063aa1a user: dan tags: trunk)
Merge latest trunk changes with this branch. (Closed-Leaf check-in: 9dca7ce557 user: dan tags: android-large-filles)
Fix typos in comments. No code changes. (check-in: e62aab5e92 user: peter.d.reid tags: trunk)

Added ext/userauth/sqlite3userauth.h.

Added ext/userauth/user-auth.txt.

Added ext/userauth/userauth.c.

Changes to main.mk.

Changes to src/attach.c.

Changes to src/auth.c.

Changes to src/build.c.

Changes to src/ctime.c.

Changes to src/func.c.

Changes to src/legacy.c.

Changes to src/main.c.

Changes to src/pragma.c.

Changes to src/prepare.c.

Changes to src/shell.c.

Changes to src/sqlite.h.in.

Changes to src/sqliteInt.h.

Changes to src/tclsqlite.c.

Changes to src/test1.c.

Changes to src/test_config.c.

Changes to test/auth.test.

Changes to test/auth2.test.

Changes to test/auth3.test.

Changes to test/fkey2.test.

Changes to test/fts4aa.test.

Changes to test/savepoint.test.

Added test/userauth01.test.

Changes to test/vtab3.test.

Changes to test/without_rowid3.test.