Lots of files ended up with indirect includes from script.h.

* Delete canonical_tests.cpp, and move the tests to script_tests.cpp.
* Split off SCRIPT_VERIFY_DERSIG from SCRIPT_VERIFY_STRICTENC (the BIP62 part of it).
* Change signature STRICTENC/DERSIG semantics to fail the script entirely rather than the CHECKSIG result (softfork safety, and BIP62 requirement).
* Add many autogenerated tests for several odd cases.
* Mention specific BIP62 rules in the script verification flags.

Edit by laanwj: `begin_ptr(sourcedata) + sourcedata.size()` -> `end_ptr(sourcedata)`

- add missing header end comments
- ensure alphabetical ordering
- update copyright year and license

Split up util.cpp/h into:

- string utilities (hex, base32, base64): no internal dependencies, no dependency on boost (apart from foreach)
- money utilities (parsesmoney, formatmoney)
- time utilities (gettime*, sleep, format date):
- and the rest (logging, argument parsing, config file parsing)

The latter is basically the environment and OS handling,
and is stripped of all utility functions, so we may want to
rename it to something else than util.cpp/h for clarity (Matt suggested
osinterface).

Breaks dependency of sha256.cpp on all the things pulled in by util.

This changes the keystore data format, wallet format and IsMine logic
to detect watch-only outputs based on direct script matching rather
than first trying to convert outputs to destinations (addresses).

The reason is that we don't know how the software that has the spending
keys works. It may support the same types of scripts as us, but that is
not guaranteed. Furthermore, it removes the ambiguity between addresses
used as identifiers for output scripts or identifiers for public keys.

One practical implication is that adding a normal pay-to-pubkey-hash
address via importaddress will not cause payments to the corresponding
full public key to be detected as IsMine. If that is wanted, add those
scripts directly (importaddress now also accepts any hex-encoded script).

Conflicts:
	src/wallet.cpp

Changes:
* Add Add/Have WatchOnly methods to CKeyStore, and implementations
  in CBasicKeyStore.
* Add similar methods to CWallet, and support entries for it in
  CWalletDB.
* Make IsMine in script/wallet return a new enum 'isminetype',
  rather than a boolean. This allows distinguishing between
  spendable and unspendable coins.
* Add a field fSpendable to COutput (GetAvailableCoins' return type).
* Mark watchonly coins in listunspent as 'watchonly': true.
* Add 'watchonly' to validateaddress, suppressing script/pubkey/...
  in this case.

Based on a patch by Eric Lombrozo.

Conflicts:
	src/qt/walletmodel.cpp
	src/rpcserver.cpp
	src/wallet.cpp

- remove some missplaced ;
- ensure end of a namespace is clearly visible
- use same formatting when using namespace

In addition, introduce a cached hash inside CTransaction, to prevent
recalculating it over and over again.

You can just use HexStr(script) or script.ToString() for debugging, no
need for these extra functions.

Since they are not real opcodes, being reported as OP_UNKNOWN is less confusing for human-readable decoding.
Signed-off-by: Huang Le <4tarhl@gmail.com>

This is a source of transaction mutability as the dummy value was
previously not checked and could be modified to something other than the
usual OP_0 value.

a81cd968 introduced a malleability breaker for signatures
(using an even value for S). In e0e14e43 this was changed to
the lower of two potential values, rather than the even one.
Only the signing code was changed though, the (for now unused)
verification code wasn't adapted.

Per mailing list discussion.