Merge branches 'jc/convert', 'jc/bigfile' and 'jc/replacing' into jc/streaming

* jc/convert:
convert: make it harder to screw up adding a conversion attribute
convert: make it safer to add conversion attributes
convert: give saner names to crlf/eol variables, types and functions
convert: rename the "eol" global variable to "core_eol"

* jc/bigfile:
Bigfile: teach "git add" to send a large file straight to a pack
index_fd(): split into two helper functions
index_fd(): turn write_object and format_check arguments into one flag

* jc/replacing:
read_sha1_file(): allow selective bypassing of replacement mechanism
inline lookup_replace_object() calls
read_sha1_file(): get rid of read_sha1_file_repl() madness
t6050: make sure we test not just commit replacement
Declare lookup_replace_object() in cache.h, not in commit.h

diff --cc cache.h
Simple merge

diff --cc environment.c
index 40185bc854ea2c5b8d2e3deb800dd6f3f44482a9,7fe9f101243d9063ff06fe2c6ea10f220b6a2549,40185bc854ea2c5b8d2e3deb800dd6f3f44482a9,91828201d87daf4c1035ac27bc6e9f07c01c8d90..94d58fd24413ec1d1a5769029bd5149b609f0d4e
--- 1/environment.c
--- 2/environment.c
--- 3/environment.c
--- 4/environment.c
+++ b/environment.c
@@@@@ -42,8 -42,8 -42,8 -42,8 +42,8 @@@@@ const char *editor_program
    const char *askpass_program;
    const char *excludes_file;
    enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
--- int read_replace_refs = 1;
- - enum eol eol = EOL_UNSET;
+++ int read_replace_refs = 1; /* NEEDSWORK: rename to use_replace_refs */
   -enum eol eol = EOL_UNSET;
+ ++enum eol core_eol = EOL_UNSET;
    enum safe_crlf safe_crlf = SAFE_CRLF_WARN;
    unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
    enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;

diff --cc sha1_file.c
Simple merge