Organization: find by name in case-insensitive

Usages of `findByOrganizationName` replaced with `findByName`
as `findByName` which finds target with name in case-insensitive
is exactly same with `findByOrganizationName`.

and this commit includes fix incorrect method name
`getVisiableProjects` to `getVisibleProjects`.
Start to develop v0.6.3

Reviewed-by:  insanehong <insane.hong@navercorp.com>
Attachment: treat error if file doesn't exists on storage

Response as 500 Internal Server Error and log it as error.
Merge branch 'fix/issue-1802' of dlab/hive

from pull-request 1287

* refs/heads/fix/issue-1802:
  Attachment: treat error if file doesn't exists on storage

Reviewed-by: 이응준 <eungjun.yi@navercorp.com>
Remove an unnecessary period
docs: Move misplaced name-validation.md
Merge branch 'docs/name-validation' of dlab/hive

from pull-request 1291

* refs/heads/docs/name-validation:
  docs: Move misplaced name-validation.md
  Remove an unnecessary period

Reviewed-by: 김지한 <kim.jihan@navercorp.com>
Merge branch 'fix/issue-1325-orgname-case-insensitive' of dlab/hive

from pull-request 1205

* refs/heads/fix/issue-1325-orgname-case-insensitive:
  Organization: find by name in case-insensitive

Reviewed-by: 백기선 <keesun.baik@navercorp.com>
Reviewed-by: 이응준 <eungjun.yi@navercorp.com>
Fix compile error after e7589df

Organization.findByOrganizationName has replaced with
Organization.findByName
Merge branch 'fix/issue-1807' of dlab/hive

from pull-request 1292

* refs/heads/fix/issue-1807:
  Fix compile error after e7589df

Reviewed-by: 이응준 <eungjun.yi@navercorp.com>
PullRequest: prevent generate unnecessary merge event
Shows admin on `Assignee` dropdown list when admin is login user or assignee.

Cause:
When `admin` assigns an issue to himself, dropdown list default value is set to `No assignee` because `Assignee dropdown list` does not include `admin` user.

Solution:
If login user is admin, he will be shown on `Assignee dropdown list`. Also an issue that assignee is admin will show admin on the list.

Private-issue: 1091
ui.Select2: fix .branche-label styles for other branch types
Issue: show proper text color .issue-label on list
Merge branch 'issue-1803' of dlab/hive

from pull-request 1295

* refs/heads/issue-1803:
  PullRequest: prevent generate unnecessary merge event

Reviewed-by: 이응준 <eungjun.yi@navercorp.com>
Reviewed-by: 김지한 <kim.jihan@navercorp.com>
Merge branch 'fix/issue-1814-issue-label-textcolor' of dlab/hive

from pull-request 1300

* refs/heads/fix/issue-1814-issue-label-textcolor:
  Issue: show proper text color .issue-label on list

Reviewed-by: 이응준 <eungjun.yi@navercorp.com>
Reviewed-by: 김덕홍 <insanehong@navercorp.com>
`Assign to me` and `Created by me` are not shown when current user is anonymous.

Cause:
Although current user is anonymous, `Assign to me` and `Create by me` are shown on `Issue` menu. But it is nonsense. Anonymous can not write any issues and not be a assignee.

Solutions:
When current user is anonymous, `Assign to me` and `Create by me` will not be shown.
For these modifications, actually, `!UserApp.currentUser().isSiteManager` is replaced to `!UserApp.currentUser().isAnonymous`. The previous codes are bug and new codes are to solve this issue.

Private-issue: 1676
Merge branch 'master-issue-1676' of dlab/hive

from pull-request 1299

* refs/heads/master-issue-1676:
  `Assign to me` and `Created by me` are not shown when current user is anonymous.

Reviewed-by: 김덕홍 <insanehong@navercorp.com>
Reviewed-by: 김지한 <kim.jihan@navercorp.com>
code: Fix incorrect listing of files in subdirectory, again

This bug is a jgit bug and I worked around it at c4f88e9 by creating
a new iterator for commits when incorrect behavior of jgit is detected.
But I made a mistake that stops iterating if the current commit is same
with the previous one. I shouldn't have done that because the new
iterator may produce a same commit as the previous one.
Merge branch 'fix/issue-1809' of dlab/hive

from pull-request 1298

* refs/heads/fix/issue-1809:
  ui.Select2: fix .branche-label styles for other branch types

Reviewed-by: 김덕홍 <insanehong@navercorp.com>