RFE: Standardize Finances Debit and Credit Implementations

[Windchild292]

This RFE calls for a standardization of the Debit and Credit implementations in MekHQ.

Ideally, they will both be implemented with the following setup:

• Implementation: Credit === (-1 * Debit)
• New Campaign Option: Limit Maximum Payment to Available Cash
• New Campaign Option: Take Loans to Fulfil (this should likely be in an enum with three or four initial cases, namely ignore potential debt (ignore any payments that will reduce the company below 0 C-Bills. This needs a rename), pay until 0 C-Bills (pay all payments until the force has 0 C-Bills, then ignore overages. Again, needs a rename), and take loans to pay for all overages. The fourth case idea is the third, but including bankruptcy as a potential bottom level.
• Implement Force Bankruptcy. This will require a bankruptcy and a maximum debt level campaign option, and further an option making this an optional campaign over condition for Against the Bot.

If this is not the case, a separate RFEs should be opened for any of the above that are not implemented as part of this.