Allow enabling of dummy error_strerror() to support some use-cases

Enable a dummy error function to make use of error_strerror() in
third party libraries easier.

Disable if you run into name conflicts and want to really remove the
error_strerror()
(cherry picked from commit 8fe40dcd7d3b46193f74032361efb674112ee9e5)

Conflicts:
	ChangeLog
	programs/util/strerror.c
Fixed timing difference resulting from badly formatted padding.
(cherry picked from commit 4582999be608c9794d4518ae336b265084db9f93)

Conflicts:
	ChangeLog
	library/ssl_tls.c
Disable debug messages that can introduce a timing side channel.

Introduced the POLARSSL_SSL_DEBUG_ALL flag to enable all these debug
messages in case somebody does want to see the reason checks fail.
(cherry picked from commit d66f070d492ef75405baad9f0d018b1bd06862c8)

Conflicts:
	include/polarssl/config.h
	library/ssl_tls.c
Fixed comment
(cherry picked from commit 86f04f400b3ce789b2a1105da1d42c39c69e47c5)
Fixed typo in base64.h
(cherry picked from commit fbb5cf9f59bde4e2dad064759a45fbfe186b46a4)
Added comments to indicate dependency from PEM on AES, DES and MD5
(cherry picked from commit 6deb37e03e698b081afcfa6feb655440eeb3cd5a)

Conflicts:
	include/polarssl/config.h
Made x509parse.c also work with missing hash header files
(cherry picked from commit 2ca8ad10a121e7d579ae935ccd9e9508604680ec)
Removed further timing differences during SSL message decryption in ssl_decrypt_buf()

New padding checking is unbiased on correct or incorrect padding and
has no branch prediction timing differences.

The additional MAC checks further straighten out the timing differences.
(cherry picked from commit e47b34bdc8507b63758402f69e7623d11dfb6984)

Conflicts:
	ChangeLog
	library/ssl_tls.c
Removed timing differences due to bad padding from RSA decrypt for
PKCS#1 v1.5 operations
(cherry picked from commit 8804f69d46ef5cb5fad403f4df8e14725966443d)

Conflicts:
	ChangeLog
	library/rsa.c
Fixed net_bind() for specified IP addresses on little endian systems
(cherry picked from commit 37286a573bd36b7d80fd101b54bd25bb04979b4e)

Conflicts:
	ChangeLog
	library/net.c
Inserted bump_version.sh in git repository
(cherry picked from commit 34558735d237335a162525a6d4ea474da06cad56)
Prepared for PolarSSL 1.1.6 release