This commit adds the `sqlite_os_trace` build tag which sets the
`SQLITE_FORCE_OS_TRACE` and `SQLITE_DEBUG_OS_TRACE` compilation
flags. This produces verbose debugging output of every operating
system call made by SQLite.

Fixes a test which did not correctly exercise the multi-statement
Queryer functionality

R.I.P. godoc.org

Always rollback on a commit error

Fix typo in README

Add support for SQLITE_ENABLE_MATH_FUNCTIONS compile-time option via the sqlite_math_functions build tag.

Co-authored-by: Dominik Kraus <dominik.kraus@nktek.de>

…d add them manually.

# Enhancement

Update `README.md` with new instructions for Mac OS cross compiling.

# Why?

The current suggested solution `xgo` is no longer maintained (GitHub archived repository).

# Credits

Credits go to Pieter Claerhout (@pieterclaerhout) and his blog post: https://www.yellowduck.be/posts/cross-compile-a-go-package-which-uses-sqlite3

Added documentation for sqlite_vtable build tag to the README.

As it was, the vtable example will give an error when adding any kind of SQL constraint in the SQL statement. Updating the BestIndex method will ensure that adding SQL constraints will not result in errors

Signed-off-by: David Vassallo <davevassallo@gmail.com>

Signed-off-by: David Vassallo <davevassallo@gmail.com>

Broken in #1085