odbc 1.4.2

• dbAppendTable() Improve performance by checking existence once (#691).

• dbConnect() no longer automatically escapes suspicious characters
  (since there doesn't seem to be a consistent way to do this across drivers)
  but instead points you to quote_value() which applies a heuristic
  that should work for most drivers (#718).

• New wrapper for dbExecute() that sets immediate = TRUE if you are
  not supplying params. That should yield a small speed boost in
  many cases (#706).

• dbSendQuery() once again defaults to immediate = FALSE (since if you're
  using it instead of dbGetQuery() you're likely to be using it with
  dbBind()). (#726).

• Deprecated odbcConnectionColumns() (in favor of dbListFields()),
  odbcConnectionActions(), and odbcConnectionIcon() (@simonpcouch, #699).

• Backend specific changes:

  • databricks: Fix schema enumeration in connections pane
    (@detule, #715).

  • Oracle: use more reliable technique to determine user/schema name (#738),
    and fix dbExistsTable() when identifier components contain _
    (@detule, #712).

  • SQL Server: improvements to dbExists() (@meztez, #724) and
    dbListTables() (@simonpcouch, #509) for temporary tables.
    It now uses column type "BIGINT" integer64 objects.

  • SQL Server with freetds driver: no longer crashes when executing multiple
    queries (@detule, #731).

  • Teradata: Fix usage of exact argument in internal methods (@detule, 717).

• On MacOS and Linux, the package will now automatically set the ODBCSYSINI
  environmental variable when using the unixODBC driver manager. ODBCSYSINI
  will not be changed if it exists already (@simonpcouch, #709).