Remove the use of String#to_d
Remove the use of String#to_d

This commit also doesn't create an needless copy if it it is trying
to typecast a value to a blob that is already a blob.  It also
changes any TypeErrors raised inside Database#typecast_value to
Sequel::Error::InvalidValues.

reubano/sequel,seeARMS/sequel,nju520/sequel,davidbegin/sequel,t-morgan/sequel,beni55/sequel,offshore-safety/sequel,uhoh-itsmaciek/sequel,gferguson-gd/sequel,yazshel/sequel,knut2/sequel,mpalmer/sequel,nicohvi/sequel,offshore-safety/sequel,offshore-safety/sequel,beni55/sequel,freshpay/sequel,nicohvi/sequel,freshpay/sequel,mpalmer/sequel,dennis-d/custom_sequel,Marketcircle/sequel,dennis-d/custom_sequel,reubano/sequel,uhoh-itsmaciek/sequel,yazshel/sequel,pfarrell/sequel,chef/sequel,tmm1/sequel,gferguson-gd/sequel,davidbegin/sequel,seeARMS/sequel,pfarrell/sequel,bigfix/sequel,t-morgan/sequel,knut2/sequel,nju520/sequel