Added new option --inject=KEY[,KEY...]

If you have a typed metadata key which contains an amount, you can use
--inject=KEY to inject a posting with that amount wherever a match
occurs.  There are two main forms of usage:

  2010-06-18 Sample
      ; Key:: $100
      Expenses:Food                $100.00
      Assets:Checking

The command would be:

  ledger reg --inject=Key

In the above, transactional form, a posting under the account "Key" will
be injected before the first posting reported for this transaction.
It's amount will be $100.  This only happens once for the whole
transaction.

It is also possible to associate the key with a posting:

  2010-06-18 Sample
      Expenses:Food                $100.00
      ; Key:: $100
      Assets:Checking

Now the injected posting is generated whenever that particular post is
reported.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/report.h b/src/report.h
index a453d351..7d725b8c 100644
--- a/src/report.h
+++ b/src/report.h
@@ -260,6 +260,7 @@ public:
     HANDLER(group_by_).report(out);
     HANDLER(group_title_format_).report(out);
     HANDLER(head_).report(out);
+    HANDLER(inject_).report(out);
     HANDLER(invert).report(out);
     HANDLER(limit_).report(out);
     HANDLER(lot_dates).report(out);
@@ -616,6 +617,7 @@ public:
     });
 
   OPTION(report_t, head_);
+  OPTION(report_t, inject_);
 
   OPTION_(report_t, invert, DO() {
       parent->HANDLER(amount_).set_expr(string("--invert"), "-amount");