Working Compound Interest

Compound interest calculations are now working.
In addition, several other small bugs were fixed.
Taking multiple loans is now handled as taking sufficient principal to
pay back the previous loans and/or refinance to a new number of
payments.
Loan repayment now handles non-integer payments and should correctly
handle closing a loan when appropriate.  it should prevent the use from
overpaying.

The calculations for "yearly" should be ok, but I didn't test it much.
Merge pull request #5 from divisionbyzero1/test-APR

Working compound interest

THE MERGE - IT'S WORKING
0.1.5 Release

-Persistent data now saves at the same time the system is saved. This
was to resolve an issue where the game froze or crashed shortly after
financials were processed but before the game saved.
-Custom intervals! you may now specify your own period in Kerbin days
from 1-9999. All values are calculated accordingly.
-Autopay is now working! You can specify the percentage of how  much of
your available Funds can be paid out automatically.
-Loans are now NOT paid automatically. They are also not figured into
the Autopay system, they must be paid manually. This is to make way for
upcoming changes in 0.2.0.
0.1.6 RC

Manual merge
Merge pull request #1 from johnqevil/APR

Apr