Maxime Levillain

This allows to set for example table names depending on the environment: `[%pgsql dbh "var=FOO" "select * from table_$FOO"]` compiled with `FOO=42 dune build` will select rows from `table_42`

Use different compat files to handle the different version of the parsetree, here the only differences are the string constants.

The whole tx_inputs_builder module is set to private, which makes impossible to use TransactionBuilder::{set_inputs, set_collateral}.

```opam install .``` ``` [drom.0.2.2] synchronised (no changes) [drom_lib.0.2.2] synchronised (no changes) The following actions will be performed: ↻ recompile drom_lib 0.2.2* ↻ recompile drom 0.2.2* ===== ↻ 2 =====...