Added support for 'UPDATE' statement using a more flexible and generic
framework for creating SQL expressions and statements.
Added documentation for the Expr object and methods.
Added documentation for the 'Update' prototype and constructor.
Added the 'equals' function to the 'Column' prototype. This is a
shortcut and cleaner way of adding 'columnName == value' expression to a
SQL expression or 'WHERE' clause. The other operators still need to be
added, but this eliminates the need to create a long, explicit
expression and pass it to the 'WHERE' function of a SQL statement.
Added support for less than, greater than, not equals, less than equals,
and greater than equals in SQL expressions and as helper functions for
SQL columns.
Tested the 'UPDATE' and 'INSERT' clause generation with use in a test
Firefox extension. In order to complete tests and ensure new framework
worked, some refactoring was needed.
Started adding support for indexed, or numbered, bind parameter to help
with defining a parameter for a literal value. Right now, literal values
are literally inserted into the SQL string instead of through the bind
parameter mechanism to prevent SQL injection attacks. However, there is
never a key provided for a literal value to use as a named parameter and
Mozilla only allows alphabet characters for named parameters, even
though SQLite allows alphanumeric.