Fix formatting in Wallet section

* Added empty line between end of paragraphs and beginning of lists
  (required by markdown for deliniation)

* Changed mediawiki sub-list item (\*\*) to markdown sub-list item
  (\ \ \ \ \*)

* Escaped OR operator (\|\|) which were accidentally creating
  multimarkdown-style tables

* Added emply lines around each list item so the list item text is
  wrapped in paragraph tags. I think this makes long list items
  easier to read.
Merge pull request #39 from harding/formatting

Fix formatting in Wallet section

[Merging formatting-only change after several hours without critical feedback.]
More minor formatting changes

* Convert HTML table to multimarkdown-style table to improve source-code
  readability and editability.

* Fix spacing errors in Merkle tree text diagram

* Use C-style source code highlighting for base58check code block

* (Not changed:) there's no support for JSON code highlighting. I tried
  javascript code highlighting, but it wasn't very useful.  All changes
  to JSON code blocks were reverted.
Fix one typo
Fix one anchor link
Add syntax highlighting to JSON blocks (thanks @saivann!)
Merge pull request #40 from harding/formatting

More minor formatting changes
Move Contracts, P2SH and multisig to a separate section
Revised contracts references out of TX Malleability section
Merge pull request #43 from harding/devcontracts

Revised contracts references out of TX Malleability section
Delete mining section stub

Please see https://github.com/saivann/bitcoin.org/issues/41
for why we decided not to include mining in the current version of
the devguide.
Move P2SH/Multisig back under Transaction
Merge pull request #44 from harding/mining

Delete mining section stub
Shorten text about chain forks
Add TODO comment about multisig/P2SH
Merge pull request #46 from saivann/devfork

Shorten text about chain forks
Use "Complex transactions" instead of "Contracts" in the Transaction subsection
Move "Standard transactions" under "P2PH script validation"
Merge pull request #45 from saivann/devcontractsp2sh

Move P2SH/Multisig back under Transaction
Apply small text improvements