Some Spider table options introduces an unnecessary complication to
Spider settings. For example, the default value of the plugin variable
spider_auto_increment_mode is -1 (use table value) and the default
table option value is 0 (normal mode). Thus, the virtual default value
of the variable is 0. This kind of indirection is confusing.

In order to delete such confusing table options in a future release,
we first change the default values of some Spider plugin variables
from -1 (use table value) to the corresponding default table values.
The default table values are defined in spider_set_connect_info_default().

At the same time, we also deprecate the option value -1 (use table value).