- fix meson build

- fix tag number - tag was not equal to PostreSQL extension version 4…

….14 x 4.15

- the result of months_between is more accurate (to Oracle) when input is timestamp. Originally
  months_between was only for date datatype, and timestamp was casted to date. Now, months_between
  is calculated correctly for timestamp too.

- fix messy work with shortlife memory context in dbms_sql

- fix trigger functions oracle.replace_empty_strings and oracle.repla…

…ce_null_strings for correct work with type char(n)

- fix upgrade script 3.13->3.14 to set correct dependency between tra…

…nsform function

  and types varchar2 and nvarchar2 - ALTER FUNCTION SUPPORT doesn't work correctly
  under CREATE EXTENSION (for some older pg)

- fix shifted test on dropped column in trigger functions

- fix crash when arguments of plvstr.rvrs specified substring out of …

…passed string

- meson support

- new functions nvl(double precision, int) and to_date(int, text)

- supports dbms_random(low, high) when low is higher than high arg (does swap)
- fix error when replace_empty_strings or replace_null_strings was executed on table with dropped columns

- fix win build

- returns NULL for empty string used as parameter oracle.to_date