Linux binary installer: Fix an error when using proxies and python 3

Fixes #1286274 [Binary linux installer fails because of bug in proxy debugging output](https://bugs.launchpad.net/calibre/+bug/1286274)
Make the raw unique identifier field available
Fix a regression in 1.26 that caused width and height attributes on <img> tags to generate CSS width and height properties without a 'px' suffix
1) Undo setting _debug as synchronized. It was already synchronized inside itself, and adding the wrapper broke getting the correct method name.

2) Import the date methods once.

3) Make date_read sync'able in both directions
1) Fix crash that is triggered by apps not using caching.
2) Don't refresh the GUI when requesting the transfer of unchanged metadata to the device.
Update Financial Times

Fixes #1286679 [Updated recipes for financial times](https://bugs.launchpad.net/calibre/+bug/1286679)
Edit Book: Fix import HTML file as new book not working on OS X
Database backend: Make the database backend more robust when the calibre library is placed on flaky filesystems. Now when an I/O error occurs while querying the database, the connection to the database is closed and re-opened and the query is retried. See #1286522 (Errors accessing SD card after suspend)
Do not try to re-open the db on IOError if the connection is in a transaction, as that will fail anyway and mask the underlying error
Fix #1286703 [minor aesthetic error](https://bugs.launchpad.net/calibre/+bug/1286703)
Linux installer: Allow using ~ when specifying the installation directory
1) Put the embedded import statements back
2) Fix syncing not to attempt to sync if either column is bad
3) Make independent syncing of the date read work
Add ability for device to do a version check for syncing.
Merge branch 'master' of https://github.com/cbhaley/calibre
Update Arguments and Facts

Fixes #1286806 [Updated recipe for arguments and facts](https://bugs.launchpad.net/calibre/+bug/1286806)
DJVU Input: When extracting embedded txt from TXTz sections in DJVU files, fix incorrect extraction of txt when the djvutxt external program is not present. Fixes #1286771 [converting DJVU file containing text fails](https://bugs.launchpad.net/calibre/+bug/1286771)
Some performance improvements for BZZDecoder
DJVU Input: A fast C based decompressor for DJVU files
...
Fix compilation of bzzdec with Visual Studio