windows build fixes
ignore unknown pragma on windows
Merge pull request #365 from da2ce7/win_fix

Basic fixes for Windows Build
OTLog: remove SleepSeconds()
Merge pull request #371 from toxeus/removeSleep

OTLog: remove SleepSeconds()
OTAccount: rename class to Account
OTAccount: rename files to Account
Merge pull request #372 from toxeus/renameOTAccount

OTAccount: rename class to Account
Identifiers: Prefix lowercase; remove the dash; use other version byte.

- Reason for lowercase prefix: "O" might be confused with "0" (is not
in the b58 alphabet for that reason).
- Reason for removing the dash: be able to double click and select the
whole identifier on all systems.
- Reason for the new version byte: eliminate the (small) risk that
someone uses the part after the prefix as a valid Bitcoin address.