#4400, #5462: Move SHA1 helpers to crypto-utils

On a way to factoring out OpenSSL support to a standalone file to ease
addition of other crypto libraries support in the future, move helpers
providing SHA1 calculation to crypto-utils.{c,h}. OpenSSL-related
functionality (SHA1 context management) is moved to crypto-utils-openssl.c.

Add new tr_sha1_ctx_t type and functions to be implemented by crypto
backends:
* tr_sha1_init - allocate SHA1 context and and initialize it,
* tr_sha1_update - hash some [more] data,
* tr_sha1_final - finish hash calculation and free the context.

Add new files to CMakeLists.txt (leftover from previous commit) to fix
CMake-based configuration.


git-svn-id: svn://svn.transmissionbt.com/Transmission/trunk@14355 f4695dd4-2c0a-0410-b89c-da849a56a58e
#4400, #5462: Move RC4 helpers to crypto-utils

On a way to factoring out OpenSSL support to a standalone file to ease
addition of other crypto libraries support in the future, move helpers
providing RC4 ciphering to crypto-utils.{c,h}. OpenSSL-related
functionality (RC4 context management) is moved to crypto-utils-openssl.c.

Add new tr_rc4_ctx_t type and functions to be implemented by crypto
backends:
* tr_rc4_new - allocate RC4 context,
* tr_rc4_free - free the context,
* tr_rc4_set_key - set cipher key,
* tr_rc4_process - cipher memory block.


git-svn-id: svn://svn.transmissionbt.com/Transmission/trunk@14356 f4695dd4-2c0a-0410-b89c-da849a56a58e