Fixes the use of PostgreSQL-style casts with ORM (soci::values)
soci::values placeholder search logic now looks for the following alphanumerical char to discard a match.
Untabfy
Fixes false negatives in case of a partial placeholder matching.
Merge remote-tracking branch 'ricardofandrade/hotfix/postgres_cast' into hotfix/3.2.2

Fixes #121
Closes #148